"Bob," said Hugh suddenly. "I know who took your automobile."

"What?" exclaimed Bob. "What are you talking about?"

"I know who took your automobile."

"Who!"

"Heinrich."

Bob burst out laughing. "What are you talking about?" he demanded. "How could Heinrich take it? Hugh, you're going crazy."

"Isn't Heinrich a German?"

"He is."

"Weren't there a lot of Germans meeting out here in the old house last night?"

"We think so. I still don't see what that has to do with Heinie."

"How do you know Heinrich wasn't here?" asked Hugh.

"You mean that Heinrich is a plotter?" exclaimed Bob, suddenly realizing what his friend was driving at.

"He might bear watching," said Hugh. "He and that German cook of yours."

"They're both honest and reliable," exclaimed Bob warmly.

"Well," said Hugh, "I heard a story last night about two men coming to a house where they had a nice 'honest and reliable' German girl and demanding to see her. The owner of the house refused, and the men then showed secret service badges. Of course when he saw the badges he had to do as they said and he called in the girl. As soon as she came into the room one of the men went up to her and grabbed hold of her hair. Well, sir, it came right off her head and then they discovered that the maid was nothing more nor less than a man, a German in disguise, trying to get information for his government."

"Is that a true story?" exclaimed Bob in amazement.

"The man in whose house it happened told it to father," said Hugh. "It only goes to show that you can't be too careful. I wouldn't be too sure about Heinrich and Lena if I were you. The Germans are a bad lot and I suspect them all."

"Perhaps," said Bob. "Still Heinie and Lena are different."

"They may be tools of Mr. Wernberg for all you know."

"You're foolish," exclaimed Bob. "Why even if they weren't loyal to the United States they'd be loyal to father and mother. I know that."

Hugh shrugged his shoulders. "It sounds fishy to me, that's all," he said. "Didn't Heinrich say he went to a party last night? How do you know the party wasn't held out here, and that he just happened to run across your car and decided to bring it home."

"If he had he would have washed the car last night, not this morning."

"Why so?"

"Because he's so methodical, like all the Germans. He never could have slept if he had known the car was dirty."

"Why, Bob," Hugh protested, "Heinrich says he didn't come in until twelve o'clock and he says the car was there then. Why didn't he notice that it was dirty then? I'd like to know."

"He probably didn't light but one light in the garage and didn't notice it."

"Sounds likely," snorted Hugh. "Take my advice and watch 'em both."

"They're just as faithful as you or I," exclaimed Bob. "You can't talk me into getting suspicious of those two."

"The faithful ones are the ones to suspect," said Hugh grimly.

"Nonsense," said Bob, but his friend's words nevertheless set him to thinking. What if Heinrich and Lena should turn out to be working in the interests of Germany? He recalled the light in Lena's room the night before, and then he thought of all the money Heinrich had had and how embarrassed and uneasy he had been when Bob spoke of it. Ugly stories of Germans crowded through his mind, but he refused to believe that their two servants were of that sort.

Presently they reached the edge of the woods. The wagon road they had followed the night before ran all the way through the stretch and a break in the trees a short distance away showed where it came out on that side.

"We must go carefully now," warned Hugh. "How far in is the old house?"

"Oh, about a quarter of a mile," said Bob. "I don't believe any one is apt to be out here in the daytime." He felt for his back pocket, however, and the knowledge that he had a revolver with him was most reassuring.

They stole along through the woods, stepping softly and keeping a sharp lookout in all directions. All was silent, however, and seemingly they were alone. Before long they were able to glimpse the old deserted house through the trees. They stopped and gazed at it intently.

It was two stories high and of wood. Years had evidently passed since any one had lived there and the house was in need of repairing. Some of the shutters were missing, others sagged or were hanging limply from the frames, the glass in most of the windows was broken, and the wind and weather had stripped practically all the paint from the sides of the abandoned dwelling. The cellar door was missing and all in all the place presented a forlorn and desolate appearance. Hugh and Bob both recalled tales of ghosts connected with the old house, and somehow now that they were there they wished they had stayed at home.

"Perhaps we ought to report this business to the police after all," whispered Hugh.

"Yes," said Bob. "Still I'd hate to go home and tell father that we didn't even go inside the place."

"That's true," Hugh agreed. "What shall we do?"

"Let's walk around it and see if we can see anything suspicious."

"All right. We'd better keep in the shelter of the woods though."

"Oh, yes, of course."

Remaining almost a hundred feet distant from the little clearing, in the center of which stood the house, the boys began to walk. Save for an occasional nervous glance about them they never took their eyes off the deserted dwelling. When they came to the wagon-road they darted across quickly, fearful lest they should be discovered. Their progress was slow and an hour had elapsed when they returned to their starting point.

"I don't believe any one is there," whispered Bob.

"It doesn't look so. Shall we go in?"

"I suppose so," said Bob, though it was plain to be seen that neither boy much relished the task. However they dared not go home and report failure to Mr. Cook, so presently they ventured forth from the woods and started across the clearing. The cellar door was open and toward this they made their way.

A gentle breeze rattled one of the shutters, causing the boys to start nervously. Bob kept his hand on his hip pocket and they walked closely together. Presently they came to the cellar steps and peered in cautiously. Their faces were pale, as gingerly they walked down the stone steps and entered the gloomy cellar.

"Flash your light," whispered Bob.

Hugh did so, and a huge gray rat scuttled across the floor, startling the boys so that they almost cried out. Little by little their courage returned, however, and they advanced a few steps. They listened intently, but no sound came to their ears. Hugh's flashlight revealed the stairs leading to the first floor and stepping noiselessly the boys approached.

Slowly and very cautiously they ascended and presently came to the top of the stairs. Bob was in the lead, his pistol gripped tightly in one hand. With his free hand he pushed the door open gently and looked within. The kitchen was deserted, a broken-down stove in one corner, a water heater covered with dirt and rust, a sagging sink, and two battered chairs and a table completing the furnishings. A soft breeze entered through a broken window and gently stirred the strip of wall paper hanging limply from the ceiling.

Bob beckoned to Hugh and they emerged into the room. They listened intently. Not a sound was to be heard. Reassured they passed out of the kitchen through a narrow back hall, and into the parlor. The same aspect of neglect and decay was everywhere evident, but nothing suspicious was to be seen.

"Shall we go upstairs?" whispered Bob.

"We might as well. I don't believe there's any one here anyway."

The stairs leading to the second floor creaked and groaned under the weight of the boys, but as they were now convinced that the house was uninhabited they were not worried. Coming to the second story they proceeded to the room located in the front of the house.

"This must be the place," whispered Bob excitedly.

A table stood in the center of the room; around it were grouped five seats, chairs and old boxes, as if five men had had a meeting or conference there.

"This is where they had their meeting last night," said Hugh. "Here are places for five men, and we saw that many come out."

"Yes, sir," echoed Bob. "This looks like headquarters."

"Suppose we could expose them," exclaimed Hugh. "Wouldn't it be great?"

"If we only could," said Bob eagerly. "Let's look around."

Pen and ink, together with a pad of writing paper were lying on the table. Besides the table and seats, however, there was no furniture in the room, and there seemed small promise of anything of interest to the two searchers. They lifted every box and searched under it, but all in vain. Finally Bob looked behind the door. With an exclamation of delight he stooped and picked up a piece of paper lying upon the floor.

"What is it, Bob?" inquired Hugh eagerly.

"I don't know. I can't see very well."

"Bring it over here by the window. It's awfully dark and gloomy in this room."

Bob followed this suggestion, and presently was reading what was written on the paper. Hugh looked on over his shoulder.

"'List of places to be attacked.'" Bob read. "'Railroad bridge, Court House, Armory, National Cartridge Company, High Ridge Steel Company. More to be added later.'"

"This looks like the real thing," exclaimed Bob excitedly. "I wonder if they plan to take these in order. At any rate we fooled them once on the railroad bridge."

"Yes," said Hugh, "and we want to fool them on the others if we can."

"They've got father's factory listed," exclaimed Bob. "I was afraid they would; the Germans don't like him. He's too good an American."

"Some one must have dropped that paper by mistake," said Hugh. "They never would have left anything like that lying around."

"Suppose they discover they've left it and come back after it."

Both boys looked nervously out of the window, but all they saw was the little clearing and the quiet trees, swaying gently under the light breeze.

"Isn't it signed?" asked Hugh.

"No."

"Look on the back; there may be something there."

Bob turned over the sheet of paper. "No writing," he said. "There's a picture here though."

"What is it?"

"I can't see very well. It looks like some sort of a bug."

"It looks like an alligator," said Hugh, taking the paper from Bob and examining it closely.

"Let me see," exclaimed Bob. "That's what it is," he announced a moment later. "What do you suppose is the idea of that?"

"I'm sure I don't know. Probably some man was just trying to amuse himself by drawing pictures, and happened to draw an alligator."

"Maybe it's a picture of Percy," laughed Bob.

"Say," exclaimed Hugh suddenly, "it's strange, though. Heinie's alligator was probably stolen by the man that returned the car, and whoever returned the car was probably out here at this meeting. What's the connection?"

"I don't believe there is any," said Bob. "You're too suspicious, Hugh."

"Won't you admit that it's queer?"

"Of course I will, but I think it also proves that Heinie couldn't have been the one who returned our car last night. That is, if you think the man who stole the alligator was the one who brought back the car. Heinrich wouldn't cry about the loss of his pet if he was the one who took it, would he?"

"It's too deep for one to understand," sighed Hugh with a shake of his head. "At any rate one thing is sure and that is that some plots are being hatched around here and—"

Before he could finish there was a loud crash behind them, the only door leading out of the room was slammed shut, and a key turned in the lock.



CHAPTER XII

TRAPPED

Bob and Hugh stared at each other in astonishment. They had been tricked and were now prisoners. A moment later they recovered somewhat from their surprise and with one accord sprang for the door.

Bob seized the knob and shook it violently. To no purpose, however.

"Get a chair, Hugh," he cried. "We'll smash the door in."

"How do we know what's waiting for us in the hall?"

"I don't care. We've got to get out of here."

There was a deafening report of a gun fired in the narrow hall. The panel of the door close to Bob's head was splintered, and a bullet shot across the room, shivering the one remaining pane of glass left in the window.

"Duck!" shouted Hugh. "Get away from that door!"

Bob needed no second urging. He sprang aside and cowered against the side of the wall. The two boys looked at each other, pale-lipped and breathing hard.

"Whew," exclaimed Hugh. "That was a close call."

Bob whipped his pistol out of his pocket, and began to crawl back toward the door.

"What are you going to do?" demanded Hugh in alarm.

"I'm going to send a bullet through there myself," said Bob. "We might just as well let them know we're alive too."

"Don't you do it. You'll only waste your bullets and it may help us later if they don't know we are armed."

Bob hesitated. "I guess you're right," he said a moment later, and presently resumed his place against the wall.

"What'll we do?" said Hugh.

"I don't know. Did you hear anybody?"

"Not a soul. All I heard was the door bang and then the pistol shot."

"I guess we're in for it," said Bob nervously.

"We must get out of here."

"I think so too, but how?"

"We can smash the door."

"Yes, and the minute we stick our heads out of the door we'll get a bullet through us. I don't see that we stand a chance."

"But we can't stay here," protested Hugh. "If we do they'll certainly fix us one way or another."

"If I don't come home to lunch father will get worried and bring help to us; he knows where we are."

"These people won't wait that long. If they are spies and plotters they'll be desperate and they won't waste much time dealing with us."

"I wonder how far it is to the ground."

"We'd break a leg trying to jump," said Hugh.

"I'll look anyway," and Bob carefully raised himself to his feet and advanced toward the window. He peered out and then suddenly uttered an exclamation.

"Hugh," he cried in a low voice. "The gray roadster is out there. A man just got in and is driving off."

With one bound Hugh was by his friend's side. "Could you see who it was?" he demanded eagerly. The roadster had disappeared down the wagon road.

"I couldn't see," said Bob. "His back was toward me all the time."

"How do you suppose that car got in here without our hearing it?"

"I don't know. Of course they had the cutout closed."

"Do you think that man has gone for help?"

"I wouldn't be surprised."

"Then now is our chance to get out of here."

"Perhaps he left a guard."

"I can't help it. At any rate we'll never have a better opportunity than this."

"Shall we smash the door in with a chair?" asked Bob.

"I don't see what else we can do."

"It's a chance."

"Of course it is, but it's no bigger chance than it is to stay here."

"All right then," said Bob. "Let's each get a chair."

They possessed themselves of chairs and then took their places one on each side of the door. They held the chairs by the backs and prepared to swing them against the panels.

"One, two, three," counted Bob, and smote the door with all the strength he could muster. A second later Hugh followed suit. The door was made of heavy oak, however, and stood fast. Bob and Hugh shrank back against the wall and waited for any result of their efforts. Silence pervaded the house.

"I guess that man was the only one here," said Hugh.

"It seems so; let's try it again."

Once more the chairs crashed against the door, but without effect. Again and again the two boys exerted themselves to the utmost, but the sole result of their efforts was to break the chairs. Finally, well-nigh exhausted, they stopped.

"It's no use, Bob," panted Hugh. "The door is stronger than the chairs."

"We've got to get out of here though."

"The only way I can see is the window."

"But we can't jump that far; we'd only break a leg or something. There isn't even a roof to help us."

"Can't we make a rope out of our clothes and slide down?"

"I say to try the door again," exclaimed Bob.

"But we can't smash it with these chairs," Hugh protested.

"I know it; let's try the table."

"How are you going to do that?"

"I'll show you," said Bob. "Take hold of this end with me."

They grasped the table and dragged it to a spot directly in front of the door and eight or ten feet distant from it. "Now," exclaimed Bob. "When I say, 'three,' we'll push it with all our might against the door."

"It'll never work," said Hugh, with a shake of his head.

"Try it," cried Bob. "We've got to do something."

They took firm hold of the table and set themselves. "Now," said Bob. "One, two, three." They pushed with all their strength and a moment later the table crashed into the door. The door creaked and groaned but did not give way.

"It won't work," said Hugh with great conviction.

"Yes, it will too," exclaimed Bob. "Stick to it."

They dragged the table back and once again drove it hurtling against the door. This time their efforts met with some success for the corner of the table drove straight through one of the panels.

"See that?" cried Bob excitedly. "I believe that if I put my hand through that opening I can reach the key and unlock the door."

"You don't suppose for a second that that man left the key in the door, do you?"

"I don't suppose he did," admitted Bob, somewhat crestfallen. "Still there's no harm in trying anyway."

"There may be somebody on guard in the hall."

"We'll have to risk that." Bob thrust his arm through the opening made in the door panel, but soon withdrew it. "The key is not there," he said.

"Of course not," exclaimed Hugh. "Get out of the way and let me get a few whacks at that panel with the chair." He attacked the door furiously and in a few moments had knocked out the panel completely.

"I guess we can squeeze through there now," he said.

"Let me go first," exclaimed Bob. "I've got a gun."

He squirmed through the opening in the door and seeing no sign of any one outside called to Hugh to follow him. A moment later they stood side by side in the dark and narrow hallway.

"We'd better get out of here as fast as we can," whispered Bob.

"The sooner it is, the better I'm pleased," returned Hugh grimly.

They stole along the hall, every sense alert. Presently they came to the head of the stairs and discovering nothing to alarm them, started down. The stairs still creaked and groaned, but the boys' confidence was rapidly returning as they neared outdoors and safety, and they hurried along.

A side door stood open and toward this they made their way. Bob had returned his revolver to his pocket for he really thought he should not need it any more. He stepped out of the doorway and started down the steps. As he did so a man sprang at him and with a blackjack dealt him a stunning blow over the head. Bob reeled uncertainly for an instant, and then sank unconscious to the floor; there he lay in a limp heap.

Before the man could deal with Bob's companion, Hugh had grappled with him, and a moment later they were rolling over and over on the ground fighting like wild cats.



CHAPTER XIII

MISTAKEN IDENTITY

Hugh had seized the man by his right wrist and as they went down the blackjack was sent spinning. It was man to man, bare hands for weapons.

Hugh's assailant was not large, but he was extremely agile. He squirmed and wriggled, kicked and butted, in fact he used every weapon at his command. Hugh probably outweighed his enemy, and in addition was a splendid wrestler, but he was young and his antagonist's strength was more developed.

Each fighter struggled desperately to get an arm free. Once Hugh succeeded, but it was his left arm, and when he seized his opponent's throat his hold was soon shaken loose. They fought fiercely, both breathing hard, their faces were red and blotched, and their eyes were staring. Over and over they rolled, the stones and twigs on the ground tearing and lacerating their hands and faces.

Hugh got hold of his opponent's right arm. He bent it back with every bit of strength he possessed, until the man cried out in pain. Hugh knew, however, that he would receive no mercy if he was overcome and he pressed home his advantage. Suddenly, with a convulsive twist of his body, the man shook loose Hugh's hold, and dealt him a heavy blow in the chest. Hugh felt his wind badly shaken and he seized his opponent around the waist with both arms, squeezing with all the strength in his body. His one idea was to keep as close to his enemy as he could, so that the man would have no opportunity to strike him again.

Gradually Hugh felt his strength slipping. He knew he could not hold out much longer, and even as he struggled he wondered how soon it would be before the other Germans returned and made an end of him. Then when he least expected it, help came to him.

Bob had opened his eyes after a moment. He had seen millions of stars, and as he came to his senses again his head felt sore and battered. He did not recall for a moment just what had befallen him. Suddenly, however, he heard the sounds of a violent struggle being waged near at hand, and sitting up he spied Hugh and his assailant locked in each other's grasp, and still fighting. Bob sprang to his feet and approached them.

He remembered everything now. His throbbing head recalled to him the blow he had received and he could feel a large lump on the back of it. He wondered what would have happened to him if he had not worn a hat. A moment later, however, he had dismissed from his mind all thought of himself and was engaged in assisting his friend.

He grasped Hugh's assailant by his throat and knelt on his shoulders with both knees. Gradually the man's strength waned; Hugh could feel it slipping. A moment later he lay gasping on the ground too weak to offer any resistance to the two boys. Hugh held his arms, while Bob released his hold on the man's throat and sat on his legs. The prisoner, his breath rattling in his chest, lay with eyes half-closed, completely done up.

Suddenly Hugh spied something that made him start violently. The man's coat lay wide open and pinned on his vest was a badge. More than that, it was a police badge, one of the badges of the police of High Ridge.

"Bob," gasped Hugh in alarm, "this man's a detective."

"What!" cried Bob. "You're crazy."

"I am not. Look here."

He released his hold on his erstwhile opponent and stood up. Bob followed suit. In amazement they looked at the man on the ground at their feet.

"That's a High Ridge police badge all right," said Bob. "No doubt of it."

"Are you a detective?" Hugh asked their victim.

The man looked at them through narrowed eyelids. "Yes," he said weakly, and started to reach towards his hip pocket.

"Here, here!" cried Hugh. "None of that! This whole thing is a mistake."

"Let me help you up," urged Bob, offering his hand to the beaten man. Hugh also assisted him and they raised him to his feet.

"I guess we were after the same people you were," exclaimed Bob, taking it for granted that the detective had trailed the Germans to the deserted house as he and Hugh had done. "They had us locked up in there and we had just broken down the door and were coming out. We didn't know you were a detective."

"You didn't give us a chance to find out," laughed Hugh, greatly relieved at the unexpected turn of events. He also felt safer to have an officer of the law with them.

The detective rubbed his neck, and looked at the two boys narrowly.

"Germans in this house?" he said at length.

"They had a meeting here last night," said Bob.

"How do you know?"

"We followed them out here. Look at this too," and he handed over the list of buildings to be destroyed that they had found in the old house.

The detective snatched the paper out of his hand and scanned it eagerly.

"Where did you get this?" he demanded.

"We found it upstairs," said Bob.

"Humph," ejaculated the detective and thrust it into his pocket.

"Weren't you trailing these Germans too?" inquired Bob.

"How do you know they were Germans?"

"Who else would want to blow up bridges and ammunition factories?"

"Did they intend to do that?"

"That's what that list says," exclaimed Hugh, nettled by the questions the man asked as well as by his odd behavior.

"Well," said the detective, "you take my advice. This is no place for a couple of boys like you to be hanging around. You might get hurt the first thing you know." He glanced about him nervously as though he expected some one else to arrive upon the scene at any moment.

"A man locked us in that room just before you arrived," said Bob. "Then he dashed off in a big gray roadster."

"Well, you'd better get out of here yourselves," said the detective shortly.

"They may come back at any minute and perhaps you'll need help," protested Bob.

"I'll take care of that part of it," exclaimed the detective. "You get out."

Convinced that there was nothing else for them to do, Bob and Hugh started off through the woods, leaving the detective in undisputed possession of the premises. They were greatly puzzled by their recent experience.

"What do you think of that detective?" demanded Bob, when they had reached a point out of sight of the house.

"I think he was an old grouch," exclaimed Hugh. "I don't see why he had to be so disagreeable to us; all we wanted to do was to help him."

"Yes, when those Germans come back he's apt to be handled roughly."

"He was jealous of us, I believe," said Bob.

"Why so?"

"Well, we had gone ahead on our own account, and from the way he acted I guess we knew more about what was going on than he did."

"Perhaps that's it," said Hugh. "Maybe he was afraid we might take some glory away from him."

"How silly!" exclaimed Bob. "What do we want with glory?"

"We'd better tell your father what happened this morning."

"Of course. He'll think I'm a pretty poor fighter though; a black eye one day and a big lump on my head the next."

"How does your head feel anyway?" inquired Hugh.

"Oh, pretty well. It still throbs though."

"I should think it might, and you can consider yourself pretty lucky that you didn't get your skull cracked open."

"He was a queer looking man, wasn't he?"

"Yes, and his actions were even queerer."

"I guess he was jealous," said Bob. "Oh, well, I don't suppose it makes any difference who corners those Germans, so long as somebody does it."

"Personally, I'm sort of glad to get away from that house," said Hugh. "I believe that if we had stayed much longer we never would have left."

"How about the detective?"

"If he wants to stay that's his lookout, not ours."

"That's right, and I suppose he'll go for help anyway."

"Perhaps they'll just watch the house for a day or two," said Hugh. "It may be though that now that those Germans know they are watched they may meet in some other place."

"True enough. I wish we could find the place."

Presently they came to the spot where they had left their bicycles. They were still there, and a moment later the boys were wheeling them back across the field again. Once more in the road, they mounted and soon were riding towards home. Their minds were busy with plots and Germans and the recent experiences they had undergone. They felt sure that they were on the trail of a desperate gang, and that quick action perhaps was necessary to prevent untold damage, and possible loss of life.

They were confused, however. Everywhere they turned they seemed to run into some new angle of the affair, or some other person who might bear watching. Hugh was still of the opinion that Heinrich and Lena should be looked after pretty carefully, though Bob laughed at him. He knew his family felt that their servants could be relied upon absolutely. Bob wondered about his father's plant; was it properly guarded? Perhaps his father might consent to let him go down there and help watch over it at night.

Talking but little they spun along the road. Each boy was occupied with his own thoughts, and consequently did not notice an automobile rapidly approaching down the road.

"Here comes a car," exclaimed Bob suddenly. They swung over to the right side of the road to let it pass, and a moment later it roared past them in a cloud of dust.

"Bob," cried Hugh excitedly. "The gray roadster."

"I know it. Did you see who was in it?"

"I didn't notice."

"Mr. Wernberg."

"What!"

"It certainly was."

"I guess your father was right about him then. He said he was a dangerous man, and I guess he is, if he's mixed up with that gang out there."

"Well, Frank wouldn't talk the way he does unless he'd heard it at home."

"Probably not. Do you suppose they recognized us?"

"Suppose they did?" said Bob, carelessly. "We have a right to the road, haven't we?"

"Certainly, but the man who locked us in the room! He must have been in the car and would surely recognize us as the ones who were in the house."

"That's true," exclaimed Bob. "Do you think they'll turn around and come after us?"

Hugh glanced back over his shoulder. "The car has stopped," he exclaimed. "Come on, Bob, we'd better ride for all there is in us."

The two boys leaned forward on their pedals, bent low over the handlebars, and rode as hard as they could. They were not far from the town now and they knew that the occupants of the gray roadster would not dare molest them, when once they had gained the populated districts. Not once did they look back until they were safely within the city limits.

"I didn't think they'd follow us," puffed Hugh. "Still it's just as well to take no chances."

"I wasn't so much afraid of them chasing us," said Bob. "What worries me is that probably they know who we are now, and consequently we won't be safe no matter where we are."

"I guess we'll have to report to the police."

"If we do I hope they treat us better than that detective did."

"I hope so, too," laughed Hugh. "At any rate we'll ask your father."

"You are coming to our house for luncheon, you know."

"Yes."

"We can talk it over with father then."

They arrived at the Cook residence without further adventure or mishap. They left their bicycles in the garage, and then started for the house. Half-way across the lawn they met Mr. Cook.

"Well, boys," he said, plainly relieved at seeing them safely back, "what luck?"

"Feel my head," said Bob, removing his cap.

Mr. Cook did so. "Whew!" he exclaimed. "Where did you get that?"

Bob related the story of their experiences that morning. Mr. Cook offered no comment until he had finished. "This looks serious," he said at length. "It's too bad you got such a bump from a detective, a man on your own side."

"What do you think of our seeing Mr. Wernberg?" asked Hugh.

Mr. Cook's face clouded and he shook his head. "I was afraid of him," he said.

"What shall we do about it?" Bob inquired.

"I think we'd better report it to the police, and do it soon, too." He looked at his watch. "We've got time before luncheon," he exclaimed. "Was Heinrich in the garage?"

"No, sir."

"How about the car?"

"That's there all right."

"Well, come along then," exclaimed Mr. Cook. "We'll get it and go straight down to police headquarters now."

"Don't you think our friend the detective will make a report?" asked Hugh.

"Possibly. Still, as Bob says, those men are sometimes very jealous and he might not tell the whole story, particularly about what you did."

A few moments later all three were on their way to the police station. Bob's old friend, Sergeant Riley, was still behind the desk and gave them a jovial greeting.

"Yez haven't got no Germans for me, have yez?" he demanded.

"No," said Mr. Cook, "we haven't, but we can tell you where to get some."

"Sounds interesting," said the sergeant laying aside his pen and carefully blotting the sheet of paper on which he had been writing. "Tell me about it."

"Go ahead, Bob," his father urged. "Tell your story, and first of all let Sergeant Riley feel the bump on your head. That'll convince him."

"It would indade," exclaimed the sergeant, after examining the swelling on Bob's head. "Not that I'd ever doubt anything a son of yours told me, Misther Cook."

Bob related the events of that day to Sergeant Riley. The police officer listened attentively and interestedly until Bob came to the part about the detective. As he began to tell of that the sergeant started perceptibly.

"A detective, yez said?" he demanded.

"Yes," said Bob, "he had a badge on."

"Can yez describe him?"

"Well," said Bob, "he was a man about five feet seven inches tall; he had dark hair and a close-cut black mustache. I should think he would weigh possibly about a hundred and fifty pounds; maybe not quite so much. He had on a soft brown hat and a dark suit of clothes. I can't remember anything more about him."

"That's a plenty," exclaimed the sergeant. He had been jotting down the description of the detective as Bob spoke.

"He was a grouchy fellow all right," exclaimed Hugh. "He chased us away from there as though he was jealous of us and didn't want us around."

"I daresay he didn't want yez," said Riley.

"What's his name?" asked Bob.

"I don't know," replied the sergeant.

"Come on, Riley," laughed Mr. Cook, "you can't tell me that. Why I thought you knew every one in High Ridge to say nothing of your own force. You don't mean to tell me you don't know a detective that wears the same badge you do?"

"Yes, sir, I do," said Riley soberly. "And I'll tell yez why. That man these boys met this morning is no detective at all."



CHAPTER XIV

AN EXPEDITION

Mr. Cook and the two boys were so completely taken aback by the sergeant's statement that for a moment all they could do was stare at one another in amazement. Bob was the first to regain his voice.

"What do you mean, Sergeant?" he demanded.

"Just what I say."

"That man was not a detective?" stammered Bob. "He is not a member of the High Ridge force?"

"There is no man answering to that description here."

"Then he was a fake."

"Exactly."

"Well," exclaimed Hugh, Bob, and Mr. Cook in one breath. They could say no more.

"He was a fake," repeated Sergeant Riley emphatically. "There is no doubt of it."

The boys were too surprised for words. What kind of a business was this they were becoming involved in anyway? The further they went the more confused they became. If you could not trust a man with a regulation police badge, whom could you trust?

"It seems incredible," said Mr. Cook.

"We are at war with Germany, aren't we?" asked Sergeant Riley calmly.

"We are," Mr. Cook agreed.

"Well, then," said the sergeant, "that explains it. They want to do us all the harm they can and as they can't bring soldiers over here, thanks to the English fleet, they've got to strike at us with plots and bombs and such things. They will stop at nothing."

"Are there many to guard against in High Ridge?" asked Mr. Cook. "You know I am interested because my factory is making ammunition for the Government."

"There are several," the sergeant admitted.

"Can you tell me who they are?"

"I cannot. 'Twould be against my orders. Yez might feel better to know that we are watching them pretty carefully though."

"I hope so," said Mr. Cook fervently.

"Have yez had lunch?" asked the sergeant suddenly.

"No," replied Mr. Cook. "Not yet."

"Well, suppose yez go home and get it. I may telephone yez a little later to go out to that house with some of our men."

"Good," cried Mr. Cook. "We'll hurry and you may be sure we'll be ready any time you call on us."

They left the police station and were soon on their way home. Arriving at the house, Hugh and Mr. Cook got out, and Bob drove the car down to the garage. There he found Heinrich seated on a box in one corner intently studying a sheet of paper he held in his hand.

"What you got, Heinie?" asked Bob cheerily. "A love letter!"

Heinrich looked up at Bob, a curious expression in his pale blue eyes. He made no comment, however, and presently returned to the perusal of the paper he held.

"What is it?" demanded Bob, impressed by the chauffeur's manner. An air of gloom seemed to pervade the garage, even the dog, the cat, and the parrot appeared to be affected by it. The dog stood listlessly by his master's side, the cat walked idly up and down, and the bird failed to greet Bob with his usual cheery "How do"; he sat limply on his perch, his feathers ruffled, and muttered to himself.

Heinrich handed the paper to Bob. It was a sheet evidently torn from a pad and in a large scrawling hand was written the following: "We warned your boss to keep his car at home; now tell him to keep his son there, too." No name was signed and Bob turned the paper over and looked at the opposite side. A picture of an alligator was drawn there. Bob recognized the sheet as similar to the one that he and Hugh had found in the deserted house and the detective had taken from them; apparently it had been torn from the same pad.

"Where did you get this, Heinie?" he demanded.

"I go up to the house to see Lena," said Heinrich. "That is maybe a half-hour ago. I only stay there a few minutes and when I come back here is this."

"Lying on the floor?"

"Yes."

"Have you no idea who sent it?"

"How should I?" exclaimed Heinrich.

"Somebody must have slipped in here while you were absent and left it," said Bob. "There are queer things happening around here these days, Heinie."

"There is," the chauffeur admitted solemnly.

"Do you mind if I keep this paper?"

"No."

Bob started out.

"You better do as that says, too," exclaimed Heinrich earnestly. "You would not want anything to happen to you."

"I'm not afraid," said Bob soberly. "You know, Heinie," he continued, "some people are trying to blow up things around here. Some of your countrymen, and we can't let them do anything like that, you know."

Heinrich seemed much perturbed at this. "So?" he exclaimed his eyes wide.

"Yes," said Bob, "and it's men like you who ought to stop them. You men who were Germans but are now Americans, could do yourselves a good turn if you did. Some people of German blood are under suspicion nowadays and if you showed that you were loyal to the United States it would be a good thing for you. Not that I mean to say we are suspicious of you," Bob hastened to add.

This speech of Bob's seemed to offer a new line of thought to Heinrich who merely stared at Bob and said nothing.

"Heinrich is so loyal himself that it never occurred to him that any one would be suspicious," thought Bob as he hurried off toward the house, the strange paper clutched tightly in one hand.

He arrived to find every one at the dining-table, and consequently he said nothing about the warning, for he did not wish to alarm his mother. She had just heard from Harold; his company had been ordered away from High Ridge that morning for an unknown destination. She was worried enough over that without having another son on her mind. Fortunately the lump on Bob's head was covered by his hair so that it was not noticeable enough to draw attention to it. His black eye already had been explained.

Luncheon was hardly over when the telephone summoned Mr. Cook. Sergeant Riley was on the wire inquiring if Mr. Cook and Bob and Hugh could not meet him at headquarters immediately. A few moments later they were in the car and on their way down the street. Bob was at the wheel.

Another car was drawn up alongside the curb in front of the police station and in it were four plain-clothes men. Sergeant Riley was there to explain that they planned to go out to the deserted house and search it thoroughly, by force if necessary. He wished the two boys to go along as guides, and he thought probably Mr. Cook would want to accompany them.

A short time later they started, Bob leading the way. As they passed Elm Street he glanced curiously at the white stucco house, number twelve eighty two, and wondered what had happened to the German who had attempted to destroy the railroad bridge. Probably he now rested in jail, awaiting trial. Then again it occurred to Bob that possibly he had been shot; the country was at war and offenders of that kind were not dealt lightly with at such a time.

They left the city behind and rolled along over the country road. The three occupants of the car were silent for they did not know what might await them at their destination. A squad of soldiers out on a hike passed them. They were hot, dirty and dusty, but their rifles glinted wickedly in the light of the afternoon sun.

"They look like business," remarked Mr. Cook.

"They certainly do," exclaimed Bob. "I wish I was one of them."

"If the war lasts long enough maybe you will be."

"The United States can certainly raise a big army."

"Indeed it can," his father agreed. "Germany thought they'd have nothing to fear from us, but they'll be sadly fooled. Just think of the money and food and equipment of all kinds we can furnish our allies; those things are just as important as men, and we can send millions of those, too, if they need them."

Presently they came to the spot where Bob and Hugh had dismounted from their bicycles that morning. Bob stopped the car and the plain-clothes detectives followed suit. Sergeant Riley took charge.

"You lead the way," he said to Bob. "We'll follow wherever you go."

A moment later they were off across the field and soon came to the woods which sheltered the deserted house. In Indian file they commenced to pick their path among the trees and underbrush. Complete silence was maintained and the party advanced, ready for any emergency. Of course the detectives were armed. Mr. Cook carried his pistol, so Bob and Hugh were the only ones not provided with some means of defense.

In the course of perhaps fifteen minutes Bob, from his position in the lead, caught a glimpse of the old house through the trees. So far as he could see there was no sign of life around it anywhere. He held up his hand and the little party came to a halt. A whispered consultation was held and it was decided to spread out somewhat and move forward in open order.

The plan was to advance until they reached the border of the trees, and then at a given signal rush out into the opening and surround the house. Stealthily the band stole forward. The spring air was soft and balmy, the buds on the trees were commencing to swell; everywhere nature gave signs of a reawakening, but these things passed unnoticed. The members of the little party were occupied with the business in hand, and had no time or interest for anything else.

Soon they reached their appointed positions. From the spot where he crouched Bob could see the others lurking within the shelter of the trees. He could see Sergeant Riley raising a police whistle to his lips to sound the signal that had been agreed upon. Bob set himself. He had been advised that inasmuch as he was unarmed he should remain behind, but he had no such intention. Neither had Hugh.

Suddenly Sergeant Riley sounded a shrill blast with his whistle. Every man rushed forward. Only for a few steps, however. A burst of flame, and a puff of smoke shot from the cellar window of the old house, and the air was rent by a terrific explosion.



CHAPTER XV

FIRE

Staggered, the men all stopped short in their tracks. An instant later there was a second explosion. There was a ripping, splitting sound, and the whole side of the building fell out. The air was filled with bits of wood and plaster.

"Keep away from that house!" shouted Sergeant Riley as one of his men darted forward. "Do yez want to get killed?"

A minute later flames appeared, and the red and yellow tongues of fire began to play around the window frames. Black smoke curled from every opening. It was plainly to be seen that the house was doomed.

"Look!" cried Hugh suddenly. "There goes a man!"

Without waiting to see what the others were going to do he dashed off in pursuit of a figure which could be seen scuttling away through the trees. Two of the detectives joined in the race and one of them fired two shots from his pistol at the fugitive. In reply the man suddenly wheeled and shot once at his pursuers. Bob heard the bullet whine past close to his head. He also had caught a fleeting glimpse of the man, and one look was enough to convince him that it was the fake detective with whom he and Hugh had struggled that morning.

A moment later the man was out of sight, Hugh and the two detectives still after him, shouting and calling to him to halt. Meanwhile the fire in the house roared and blazed.

"She's a goner," said Sergeant Riley. He stood beside Mr. Cook and Bob as they watched the burning building.

"I guess she is," remarked Mr. Cook. "There's nothing we can do."

"Nothing," agreed the sergeant.

"It's not much loss anyway," said Mr. Cook.

"No loss at all," exclaimed Bob. "It's a gain if anything, for it makes one less place for spies and plotters to meet in."

"But any evidence that might have been in there is destroyed," said Riley.

"I never thought of that," said Bob. "That's probably why they burned it."

"Was that your detective running off through the woods?" asked the sergeant.

"It certainly was," said Bob. "I guess he was one of the gang after all. I suppose they left him behind to watch us."

"Then why did he let you get away?" his father replied.

"Probably he thought it would create less suspicion," said Sergeant Riley. "He got the paper away from the boys and as long as he thought he could bluff them into thinking he was a detective he thought that was sufficient. On the other hand if he had held them prisoners or anything like that there would have been a search for them and trouble started at once."

"I guess that's right," said Mr. Cook soberly. "However, I hope they catch him this time."

Suddenly a piercing scream startled them. They glanced up to see a white face at one of the windows of the house. All around, the fire roared and the smoke curled up in great clouds. Before they could see who the man was he had fallen back into the room and disappeared from view.

"I'll get him," exclaimed one of the detectives, and without further ado, he sprinted for the burning house. Paying no heed to the warning cries of his comrades he dashed up to the back door and entered, and was soon lost to sight.

"That feller Donovan is a dare-devil," exclaimed Sergeant Riley. "He'll stop at nothing. Why should he risk his life for a man that's as good as dead now?"

"He'll never come out alive," cried Mr. Cook.

"And all for a man who is plotting against the country," echoed Riley. "Here you!" he shouted to the other plain-clothes man. "Keep out of there. The High Ridge police force can't afford to lose more than one man a day." The fourth detective showed signs of wishing to follow his comrade.

"If he does rescue that man it'll only be to put him in jail," said Bob.

"Or shoot him more likely," cried Riley angrily.

Breathless they waited for any sign of Donovan. The fire burned more fiercely every moment, and it seemed incredible that any man could enter that seething furnace and return alive. The air was filled with sparks and blazing embers; the smoke mounted heavenward in a thick column which must have been visible for miles.

Minutes that seemed like hours passed. Hugh and the two detectives returned from their chase. They had not captured their man.

"We followed him as far as the road," one of them reported. "He had a motor cycle there and got away from us."

"We'll get him later, never fear," said Sergeant Riley, grimly. "Meanwhile that crazy man, Donovan, is in the house here trying to rescue some one of them German plotters that showed his face at the window."

The recipients of this piece of news gasped. "He'll never come out," exclaimed one of the men. "Still, he never did seem to care much for his life."

White faced and tense they watched the conflagration. Certainly not one of the men ever expected to see Donovan again. Yet what could they do? As Sergeant Riley had said, it was folly for any one else to follow him in, and so they were powerless. All they could do was watch and hope.

Suddenly a figure appeared at the door. It seemed to issue straight from the hottest part of the fire. On its shoulder was the limp figure of a man.

"There he is!" cried six voices together, and together the six watchers made for the house.

Donovan, for it was he, stood on the charred steps. Sparks and blazing firebrands fell all around him and he tottered uncertainly. Willing helpers rushed to his assistance, but before they could reach him he swayed and fell. He rolled down the step dropping his burden, and side by side the two men lay on the ground. Close by, the wall threatened to fall on them at any moment.

It did not take long to seize both men, and carry them away from danger and a moment later they were stretched out side by side on the grass, a safe distance from the burning building.

The man whom Donovan had rescued, had a face so blackened by smoke and soot that he was unrecognizable. His clothes were scorched and his whole body seared with terrible burns. He was unconscious.

"Is he still alive?" whispered Bob in a low voice.

Sergeant Riley put his hand over the wounded man's heart. "I think so," he said. "Get some water somebody. And look after Donovan."

"There's a spring back there in the woods," exclaimed Hugh. "I have nothing to carry water in though."

"Take all the handkerchiefs you can get," ordered the sergeant. "Fill the hats; you'll lose most of it on the way back, but you'll get some."

Hugh hastened to obey; with him went Bob and two of the detectives. The spring was not far distant, and they soon were sousing the handkerchiefs in the clear, cold water. The hats, too, were filled and those made of felt held the water fairly well. A few moments later they were hurrying back toward the spot where the injured man was lying.

It had been found necessary to remove the patients farther away from the burning building, for the heat grew more intense every moment. Donovan had so far recovered as to be sitting up. He suffered acutely from numerous burns, but otherwise seemed to be all right. The man whom he had rescued, however, still lay unconscious on the ground.

Sergeant Riley now took charge of the operations. He bathed Donovan's face with one of the handkerchiefs and gave him another to suck. Mr. Cook under Riley's instructions poured water from one of the hats upon the other sufferer's face, and then gently sopped it with a handkerchief. As a result of this treatment the soot and grime disappeared and presently it was possible to distinguish his features.

Suddenly Mr. Cook started back in surprise. "Come here, Bob," he cried. "See who this is."

One glance was enough for Bob. He recognized the man over whom his father was working as Mr. Wernberg.



CHAPTER XVI

MORE COMPLICATIONS

"Who is he?" inquired Sergeant Riley, noting his companion's astonishment.

"His name is Wernberg," said Mr. Cook.

"I've heard of him," said Riley grimly.

"Have you been looking for him?"

"I know his name," exclaimed the sergeant evasively.

"Well," said Mr. Cook, "he's about done for, I'm afraid. I suppose we ought to get him to a doctor as fast as we can though."

"Yes," agreed Riley.

"I'll get our car," exclaimed Bob.

"Can you bring it in here?" asked his father.

"Yes. I'll have it here in ten minutes," and Bob set off at top speed through the woods toward the spot where the automobile had been left.

Mr. Wernberg was still unconscious. In fact it was difficult for a time to ascertain whether or not he was alive. More water was brought from the spring and Mr. Cook and Riley continued to minister to the sufferer. Some of the worst of his burns were bound up with strips of shirts offered by members of the party, and his outer clothing was removed. As a matter of fact a large portion of it was so burned that it crumbled to powder at a mere touch.

"He's alive," said Sergeant Riley after a few moments.

"Then he ought to recover," exclaimed Mr. Cook. "That is, unless he has inhaled some of the flames and injured his lungs in some way."

"Only a doctor can tell that," said the sergeant. "Whether he gets well or not, one thing is certain and that is he'll be in the hospital a long time."

"That's right," agreed Mr. Cook. "I wish he could talk though."

At that moment Bob arrived with the automobile and presently Mr. Wernberg was lifted into the tonneau and a blanket wrapped around him. He was still unconscious, but his face was drawn with pain that fortunately he could not feel. Much as the men who cared for him despised him for his suspected work with the gang of spies and plotters they could only feel pity for his sufferings.

Mr. Cook, Hugh, and Sergeant Riley accompanied Bob on his trip to the High Ridge Hospital, and the three other members of the party were left to watch the fire and see that it did not spread, and then they were to follow in the other car. Donovan the detective seemed to be himself once more and related briefly the story of how he had rescued Mr. Wernberg.

"I rushed into the house," he said, "and as I stuck my head inside the door a wave of smoke caught me full in the face. At first I expected I should have to turn back, but I kept on and presently the air cleared for a minute. I knew the trapped man was on the second floor so I hurried around looking for the stairs. Finally I found them and though they were awfully rickety I got up.

"The smoke seemed to be thicker on the second floor and I could scarcely see. I heard a cry and followed it, stumbling and falling along the hall. The door of one big room was smashed and the smoke poured out of there as if it was a chimney. No one was in that room and I came out into the hall again. I heard another call, and traced it as coming from a room where the door was closed. I grabbed the door-knob, but it was locked. 'Help! Help!' I heard from inside. 'Unlock the door!' I shouted. 'I have no key,' said the voice, so I put my shoulder to the door and tried to force it.

"I was choking and coughing and gasping, what with the smoke and all, and it was hard work standing there. I shoved with all my might though, and all of a sudden the door gave way. I went shooting into the room and fell right over a man stretched out on the floor. 'They blew me up,' he cried and fainted. Well, the room was full of smoke and all around the edges little tongues of flame were playing; the fellow had fallen to the floor and been terribly burned. I picked him up and staggered out with him and you know the rest."

Donovan himself was badly burned about his hands and face. Every one knows how painful is a burn, but the detective made no complaint, in spite of the fact that he must have been suffering agonies.

Meanwhile Bob was speeding the car back towards High Ridge. He broke all speed laws on the way, but he had been warned that haste was imperative if Mr. Wernberg's life was to be saved. Besides he had a police officer in the car with him and knew that he was safe.

In an incredibly short time he pulled up in front of the hospital. Two orderlies were summoned, and soon Mr. Wernberg, placed on a stretcher, was being carried into the building. Once or twice his eyelids fluttered as though he were about to regain consciousness, but he did not seem to possess sufficient strength to accomplish that end.

Two doctors hastily took him in charge, Sergeant Riley left word that he should be summoned the instant the patient was able to talk, and then Bob ran the car around to police headquarters. Sergeant Riley invited them all into his office and they discussed what their next move should be.

A band passed by the door, several men in uniform followed behind on their way to the city square where they were to make speeches in order to urge more enlistments in the army and navy. Crowds of enthusiastic people trailed the procession, and Bob could not help wondering if the people realized that danger threatened the country from within as well as from without.

Presently the car bearing the three detectives arrived at headquarters. They reported that nearby farmers had come to the scene of the fire, which was now in such condition that no harm could come from it. The farmers had promised to watch over the smouldering ruins, for ruins were now all that remained of the old house.

Donovan once again related his story and then went off in search of a doctor to care for his burns.

"It's bad business, Sergeant," said Mr. Cook.

"It is," Riley agreed. "I'd like to get me hands on some of them fellows."

"Seems queer that they should have blown up one of their own men."

"'Twas probably a mistake. Perhaps they saw us coming and were in such a hurry that our friend Wernberg had no time to get away."

"But look here," protested Bob. "Don't you remember what Donovan said that Mr. Wernberg said when he burst into the room?"

"He said, 'they tried to blow me up,'" quoted Mr. Cook.

"Exactly," exclaimed Bob. "Doesn't that seem queer to you?"

"He was probably left there by mistake, as the sergeant says," said Mr. Cook.

"But," Bob insisted, "the door was locked."

The men looked at one another blankly.

"I had forgotten that," said Sergeant Riley.

"Well," insisted Bob, "I'd like to have that part of it explained to me. You don't suppose for a minute that Mr. Wernberg locked himself in, do you?"

"I shouldn't think he would," Mr. Cook admitted. "But if he didn't do it, who did? That's what I'd like to know."

"Mr. Wernberg wasn't the only man in the house, you know," said Bob.

"Who else was there?"

"Didn't Hugh and two of the detectives chase another man?"

"Yez mean the fake detective?" asked Sergeant Riley.

"I do."

"But wasn't he in the same gang? What use would it be to him to blow up one of his own men?"

"I don't know," said Bob. "Still I don't believe that Mr. Wernberg locked himself in and threw the key out of the window."

"Doesn't sound likely," the sergeant agreed. "I'd like to know why those two men were enemies though. From all I can learn I should think they were working for the same purpose. Why should that fake detective be so eager to get that paper away from yez, and to get you boys away if he wasn't up to something suspicious?"

"Don't ask me," exclaimed Bob. "It's too deep for me, and I get more and more mixed up all the time."

"Well, I believe it's just as I said," continued Riley. "They were both parts of the same crowd. There must have been evidence against them in that house and they wanted to destroy it. Your fake detective blew it up and Mr. Wernberg got caught in there by mistake."

"How do you explain the locked door?" asked Bob.

"I don't, but there must be some explanation for it."

"You think it was an accident, don't you?"

"I do," said Sergeant Riley firmly. "When Mr. Wernberg gets so he can talk I'll bet he'll say the same thing."

Bob merely shrugged his shoulders. He did not think that the sergeant's explanation was correct, but he could offer no better one himself so he said nothing. After all it might be that in the hurry to get away there was a mix up and Mr. Wernberg was left behind, locked in the room. Bob had no doubt in his mind that Mr. Wernberg was a member of a gang that was plotting against the United States. In his heart he felt sure he was guilty.

On the other hand if the fake detective was not equally guilty he would be surprised. Certainly no man would disguise himself in that way who had honorable motives. Nor would any man run away as he had done, or fire a pistol at real officers of the law unless he was engaged in some evil doing.

How were these two men connected? That was the question that bothered Bob. He felt that there was some connection between them, and yet why should one of them be locked in the second story of a house while the other one put a bomb under it and burned it up? Perhaps after all it was as Sergeant Riley had suggested.

"Come on, boys; we'll go home," exclaimed Mr. Cook.

"Thank yez for coming with us," said Sergeant Riley, as Mr. Cook and the two boys rose to their feet preparatory to leaving.

"Not at all," said Mr. Cook cordially. "If there is anything further we can do to help, please call on us."

"I will," said the sergeant. "Thank yez again."

"And don't forget to let us know what Mr. Wernberg has to say."

"I won't."

They went out and got into the automobile and a few moments later were home again.

"After you put away the car, I want you to take a note down to the Wernbergs for me," said Mr. Cook to Bob as he mounted the steps of the house.

"To tell them what happened to Mr. Wernberg?"

"Yes."

"I should think it would be better to go and see them."

"No doubt it would, but somehow I don't like the idea of having to go and talk to Mrs. Wernberg about it. I suppose I'm a coward."

"I don't blame you," exclaimed Bob, and after he had returned the car to its place in the garage he came back to the house to wait until his father should have finished the note he was writing.

When it was ready Mr. Cook handed it to Bob, who at once started for the Wernbergs' house, accompanied by Hugh. They discussed the recent turn of events in the mystery and were somewhat at a loss as to what their next move should be. Now that the old deserted house was a thing of the past they did not know where to look for the seat of the conspiracy. They did decide, however, that in so far as it was possible they would keep watch on number twelve eighty-two Elm Street.

They mounted the front steps of the Wernbergs' house, and Bob advanced toward the door bell. Before he rang it, however, he spied an envelope lying at his feet, half concealed under the door mat. He stooped to pick it up, and as he glanced at it he uttered an exclamation of surprise.

"Look, Hugh," he exclaimed.

The envelope was of plain white paper and addressed to Mr. Wernberg. There was no street number on it, merely the name. This in itself was not particularly odd, nor was it the cause of Bob's surprise. On the other side of the envelope, however, was scrawled a drawing. It was the picture of an alligator.



CHAPTER XVII

A MESSAGE

"Well, Hugh, what do you think about that?" demanded Bob.

Hugh looked blankly at the rude drawing on the back of the envelope. "I don't know," he said slowly. "Why should they send Mr. Wernberg one of these?"

"Unless it's a message from one member of the gang to another."

"But Mr. Wernberg is in the hospital."

"The others may not know that."

"That's true," Hugh agreed. "This handwriting is the same as that on the messages that came to your father and to Heinrich too."

"I know it, and the same as in the list we found in the old house."

"What do you suppose the alligator stands for?"

"I've no idea. Why did they steal Percy?"

"Anyway we'd better ring the bell and deliver our message. We can't stand out here on the porch all day, you know."

Bob pushed the electric bell, and almost instantly the front door was opened by Frank Wernberg. It would seem as if he had been behind the door waiting all the time. His close-cropped light hair bristled fiercely, and his nose was still slightly swollen; his chin also was still raw where Bob had planted his fist the day before. Bob thought how much longer ago than that it seemed; so many things had happened in the last two days.

"What are you doing here?" demanded Frank brusquely.

Bob and Hugh had been so surprised by the sudden opening of the door that for a moment neither one of them replied.

"What do you want?" exclaimed Frank.

"We've got a letter for your mother," said Bob.

Frank glared at them under lowering brows. "Who from?" he asked.

"That's for her to find out," said Bob. "It's addressed to her you see."

Frank snatched the letter from Bob's outstretched hand, and made as if he was about to go in and shut the door.

"Wait a minute," exclaimed Hugh. "Here's another."

"What kind of a joke are you trying to play on me?" cried Frank angrily.

"None at all," said Hugh. "This one is for your father."

Frank grew red in the face, "If this is a joke I swear you'll be sorry for it," he exclaimed hotly.

"It's no joke at all," said Hugh. "We found this letter lying here under the mat. I was just going to hand it to you."

Frank took the letter from Hugh and looked at it suspiciously. Then he turned it over and looked at the back of it. Suddenly he turned pale.

Bob and Hugh, watching him closely, noticed this fact, and Bob, suddenly plucking up courage, determined to speak of it.

"What does that alligator mean, Frank?" he asked.

The color rushed back into Frank's face. He looked as though he were going to run. He swallowed hard two or three times, choked, and then swallowed again. "I don't know," he blurted out finally, and stepping inside slammed the door shut in the faces of the two boys.

Hugh looked at Bob and smiled. "Frank was certainly glad to see us, wasn't he?" he said sarcastically.

"I should say so," Bob agreed. "Let's go home."

They went down the steps and walked slowly in the direction of the Cook home.

"Frank's a queer fellow," said Hugh finally.

"He certainly is," Bob agreed.

"Do you think he knows what has happened to his father?"

"I doubt it. I don't believe he would have been so surly if he had known."

"What do you think about the alligator?"

"I'm sure I don't know," said Bob. "It must mean something though, and Frank must know what it is. Did you see how pale he got when he saw it!"

"Maybe it's the sign of some secret society like the Black Hand, or the Ku Klux Klan, or something like that."

"Still I can't understand why they should send a warning to Mr. Wernberg if he is a member of the gang."

"It may not have been a warning," said Hugh. "Perhaps it was just a message of some kind or another."

"Then why should Frank have been so scared when he saw it?"

"Don't ask me. I'm getting more mixed up every minute."

They turned into the Cooks' yard and slowly approached the house. A man and woman were just disappearing around the corner.

"Who are they?" Hugh inquired.

"Lena, the cook, and one of her beaux," said Bob.

"I thought Heinrich was in love with her."

"He is," laughed Bob, "but he has a rival, and that's the man."

"What's his name?"

"Karl Hoffmann."

"Another German," said Hugh soberly.

"Say, Hugh," laughed Bob, "you certainly are suspicious. You suspect good old Lena, and now you suspect the man with her because he has a German name. Why, that man Hoffmann has worked for father for years, and father thinks the world of him."

"That doesn't mean he may not be mistaken," Hugh insisted.

"Why, father has even selected him as one of the guards for the factory," said Bob. "I guess that shows how much confidence he has in him."

"But suppose Lena is disloyal," exclaimed Hugh. "If Karl Hoffmann is in love with her there's no telling what she might get him to do."

"But Lena is not disloyal," said Bob peevishly. He was becoming tired of Hugh's constant slurs against the people whom his father employed.

"Well, I'd watch them all," said Hugh.

Bob offered no further comment. He could not convince Hugh that his suspicions were unfounded so he decided there could be no use in arguing with him. They entered the house and found Mr. Cook seated in the library alone.

"Did you deliver my note?" he asked.

"We did," replied Bob.

"Who came to the door?"

"Frank," and Bob related their experiences to his father. Mr. Cook was much interested and puzzled by the manner in which Frank had acted when he saw the drawing of the alligator on the back of the envelope.

"We thought perhaps it might be the sign of some secret society," said Hugh.

"Possibly so," agreed Mr. Cook. "Let's see; the same sign was on the paper you found in the old house, Heinrich got a note with the picture on it, and now this letter you picked up on the Wernbergs' porch had it too."

"And the handwriting was the same as on that postal card you got this morning," said Bob.

"I didn't see any picture on that though."

"No," agreed Bob. "Neither did I."

"I threw the card away," said Mr. Cook. "I was afraid your mother might find it and worry."

"Perhaps there won't be any more trouble, now that Mr. Wernberg is out of the way," suggested Bob. "If he was the leader of the gang, his burns will keep him in the hospital and out of mischief for some time to come."

"You didn't hear what happened this afternoon then?" asked his father.

"No, what?" demanded Bob and Hugh in one breath.

"You remember the railroad bridge, don't you?"

"I guess we'll never forget that, will we, Hugh?" exclaimed Bob. "You don't mean that they tried to blow it up again?"

"Well, it looks so," said Mr. Cook. "One of the guards on the bridge this afternoon saw a man coming down the river in a rowboat. He called to him to halt, but the man kept right on. The guard challenged him three times, but as the man gave no answer he fired at him."

"Did he kill him?" demanded Bob excitedly.

"No," said Mr. Cook, "he didn't try to kill him. He just wanted to scare him, and when he fired the man jumped out of the boat into the water. The guard hurried down to the bank of the river, but the man had scrambled ashore and run off; you know it's quite a long distance from where the railroad tracks cross the bridge down to the water. The guard got a long pole and waded out into the river after the boat. He caught it finally and when he had hauled it ashore he found it was loaded with dynamite. Of course no one knows, but they think he planned to blow up the bridge."

"Whew!" exclaimed Hugh. "The man got away, you say?"

"Yes, unfortunately."

"Couldn't the guard see what he looked like?"

"Yes, he did see that, and here is the interesting part."

"What do you mean?"

"Why," said Mr. Cook, "the man was rather slight, weighing perhaps a hundred and fifty pounds and he had a close-cropped black mustache."

"The fake detective!" exclaimed Bob. "Was that who it was?"

"The description fits him, doesn't it?"

"Yes," agreed Hugh, "but he was out at the old house this afternoon. How could he be on the river at the same time?"

"He was out at the old house early this afternoon," said Mr. Cook. "This episode at the bridge happened only about an hour ago."

"He must have hurried right down there," exclaimed Bob. "When he realized that the police were on his trail he probably decided he had no time to lose, and that's why he dared try such a thing in broad daylight."

"Where did you hear about it, Mr. Cook?" inquired Hugh.

"Sergeant Riley just told me over the telephone; I had called him up to inquire how Mr. Wernberg was getting along."

"How is he?" asked Bob.

"Pretty bad yet; once in a while he recovers consciousness, but only for a few minutes. Besides he suffers so from his burns he can't do any talking."

"And meanwhile his gang keeps on working," said Hugh.

"Is that fake detective part of his gang?" said Bob. "He's the one who blew him up."

"I don't know," exclaimed Hugh in despair. "We just go 'round and 'round in circles and don't seem to get anywhere at all."

"But the fact remains, doesn't it, boys," inquired Mr. Cook, "that whether we know who the gang is, and what the relations are between the two gangs—if there are two—that somebody is hard at work plotting against this country? Also they are becoming bolder for they know that their time is short; sooner or later they are bound to be caught."

"You're afraid for your factory to-night, aren't you, father?" asked Bob.

"I am, indeed," said Mr. Cook.

Bob was on the point of asking if he and Hugh might not help guard it when the telephone rang and his father was called away to answer it.



CHAPTER XVIII

KARL HOFFMANN

"Let's go down and talk to Heinrich," exclaimed Bob when his father left the room.

"Aren't you going to ask your father if we can stand guard to-night?"

"Wait till after dinner. I'll ask him then."

"Do you think he'll let us?"

"I guess so. It depends on how badly he needs us."

They went out, and just at the corner of the porch met Karl Hoffmann. He had said good-by to Lena and was on his way home. Bob knew him well, as he did most of his father's employees, for much of his spare time was spent down at the factory. Furthermore, on account of Lena, Hoffmann was a frequent visitor in the Cook home.

He was a big, fine looking fellow of about forty. He had black hair and a piercing black eye, a typical Prussian, for it was from that province in Germany that his parents had migrated some twenty-five years previously. He was a powerful man, standing nearly six feet in height, and not yet showing any tendency towards stoutness, so common among Germans.

"Hello, Karl," cried Bob cheerily.

Hoffmann stopped short. His face had been drawn into a scowl as he strode along, and he had been deeply engrossed in his own thoughts. Bob had often seen him that way after talking with Lena, however. She was something of a flirt and received lightly her admirers' advances. Many a time both Heinrich and Karl had been driven almost to desperation by the manner in which she treated them. Neither did they like each other, because they were rivals.

"Hello there, Bob," he exclaimed, his face brightening. Bob had always been a marked favorite of his, and many a thing he had showed him about the machinery at the factory.

"You look mad," said Bob.

"I was sort of mad," said Karl. "I was worried."

"Anything I can do for you?" Bob inquired, nudging Hugh with his elbow. He loved to tease both Karl and Heinrich about their love affair.

"No, thanks," replied Karl seriously. "It will be all right I hope."

"I hear you're making ammunition down at the factory," said Bob.

"Yes."

"Keeps you pretty busy, doesn't it?"

"It certainly does. We're going to work both a night and day shift next week."

"You want to watch out for some of these bomb plotters," said Bob. "There are a lot of them around here, I understand."

"That so?" exclaimed Karl. "I hadn't heard of any."

"Well, they're here all right."

"We have the plant guarded, you know."

"I know it. It's a good thing too."

"I think it's unnecessary," said Karl. "I told your father so, too."

"You're more of an optimist than he is, I guess," laughed Bob. "He's heard a lot of things that have made him sort of nervous."

"That so?" demanded Karl. "I wonder what they were?"

"I don't know," Bob lied. He thought that if his father wanted to tell his employees any details he would probably do so himself.

Just then Hugh plucked his sleeve. "Look, Bob," he exclaimed. "Here comes Frank in to see you."

Bob swung around just in time to see Frank Wernberg on a bicycle turning into the driveway. He rode a few yards and then suddenly turned around and rode out again. Coming to the street once more he dismounted from his bicycle, and gazed back at the Cooks' house as if he was debating whether he should go in or not. Finally, however, he seemed to decide against that course and jumping on his wheel rode off down the street.

"He lost his nerve," exclaimed Hugh. "You ought to have called to him."

"A fine chance of that," snorted Bob. "If he wants to he can come in here and see me, but I won't run after him."

"Who was that boy?" asked Karl curiously.

"Frank Wernberg," said Bob.

"Wernberg?" exclaimed Karl. "Does his father live down on the corner here?"

"Yes."

"I don't like that man," said Karl soberly. "I hope he's not a friend of yours."

"He is not," exclaimed Bob warmly. "What do you know about him, Karl?"

"Nothing much; I just don't trust him."

"No one seems to like him," laughed Bob. "I guess he won't bother us for some time to come though now."

"Why not?" demanded Karl quickly.

"He's sick."

"What's the matter with him?"

"I don't know," said Bob evasively. He suddenly remembered that probably he had no right to talk about what they had done that day. "All I know is that he's in the hospital."

"Serves him right," exclaimed Karl. "That's a good place for him and for all of his same kind."

If Hugh had had any lingering doubts as to whether or not Karl was loyal they were now dissipated. If Mr. Wernberg was implicated in German plots against the United States, certainly no man who sympathized with him would hate him as Karl Hoffmann plainly did.

"We may come down and help you guard the factory to-night, Karl," said Bob. "You'll be there, won't you?"

"Yes, I'll be there," said Karl. "I wish you wouldn't come though."

"Why not!"

"Suppose something should happen and you got hurt?"

"I thought you said there was no danger."

"I don't think there is, but I know your father doesn't agree with me, and if something should happen to you, just think how badly he'd feel."

"We want to help though," insisted Bob.

"Let the men who are paid for it do the guarding."

"But it's my father's plant," said Bob. "You don't think I want anything to happen to it if I can help it, do you?"

"If he wants you to come, all right," said Karl. "Still you take my advice and stay home."

He said good-by to the boys and went off toward his house. He had to be at the factory early and wanted his supper before he went on duty.

"Well, Hugh?" demanded Bob after Karl had gone. "What do you think of him?"

"Oh, he's all right," said Hugh.

"Do you think he would be disloyal?"

"No, I guess any man who hates Mr. Wernberg as much as he does can't be pro-German. Still he was funny about not wanting us at the factory to-night."

"I know why that was," exclaimed Bob. "He thinks we're just a couple of kids and would only be in everybody's way."

"I guess so," Hugh agreed. "He seemed like a nice fellow all right."

"He is, but Heinie doesn't think so. Let's go ask him about Karl now, and I'll guarantee you'll see some fun. Heinie gets mad the minute you mention his name."

"He's jealous of him, isn't he?"

"He surely is. Lena likes Karl better than she does him, I think, and I guess Heinie knows it. That's why he doesn't like Karl."

"Still I don't blame Lena," observed Hugh. "Karl is certainly better looking."

They found Heinrich seated on a chair in the garage busily counting over a large pile of bills. When the boys appeared he showed the same embarrassment he had when Bob had surprised him at the same work before.

"The rich man again," laughed Bob, but Heinrich said nothing.

"Any trace of Percy?" Bob inquired.

"No," said Heinrich sorrowfully. "I guess he iss gone."

"We've just been talking to Karl Hoffmann," said Bob. "You don't suppose he could have stolen him, do you?"

Immediately Heinrich's manner changed. He rose to his feet angrily, while Bob nudged Hugh. Heinrich became pale with rage.

"That scoundrel!" he stammered. "I would not be surprised if he would steal poor Percy. He iss mean and low enough to do anything."

"Why, Heinie," said Bob mildly. "I always thought Karl was a fine fellow."

"He iss a low down snake!" cried Heinrich. "I would not trust that fellow mit two cents."

"Lena likes him," said Bob.

Heinrich became madder than before at this remark. He stuttered with rage, and advancing toward Bob shook his clenched fist in his face. "Sure she like him," he cried. "Why not? He gives her presents all the time and it iss for that that she like him. She knows what a low down cur he iss, for I have told her so. Only because he has money and can give her presents does she like him. But I will show her!"

"What are you going to do?" demanded Bob, somewhat alarmed by the violence of Heinrich's manner.

"I buy her presents now," exclaimed Heinrich. "You see that?" he demanded, pulling the roll of bills out of his pocket. "You see that?" he repeated. "Well, I got some money now, and I show her who can buy nice presents. She like me better than Hoffmann when I get more money than he." Heinrich looked at the bills held in his fist, and then jammed them back fiercely into his pocket.

"Where'd you get all the money?" asked Bob. "You didn't draw it out of the savings bank, did you?"

"No," exclaimed Heinrich. "I earn it."

"Working for father?"

"No, for Mr. Wernberg."

"What!" exclaimed Bob, completely taken by surprise. He and Hugh looked at each other in astonishment. This was a new turn of events.

"Yes," said Heinrich. "I do some work for Mr. Wernberg; he iss a fine man too."

"What was the work?" inquired Bob. He remembered that Hugh had advised him to watch their chauffeur. He never imagined, however, that even if Heinrich was guilty he would be so bold as to confess brazenly that he was employed by a man to plot against the United States. Still, he had always suspected that poor Heinrich was not quite right in his head.

"I cannot say," said Heinrich. "The work iss secret."

"Why, Heinie," exclaimed Bob. "I never thought you would do a thing like that."

"Why not?" demanded Heinrich. "I do my work here, don't I? Why should I not make a little extra money if I can?"

"But Mr. Wernberg is a bad man."

"He iss not," Heinrich protested stoutly. "He iss one man who knows right from wrong."

Bob shook his head sorrowfully. It hurt him to discover that their chauffeur, a man he had grown up with and liked, was working hand in glove with Mr. Wernberg. He never would have believed it possible had he not heard it with his own ears from Heinrich himself. It was a great shock to him and he knew how badly his father and mother would feel. Of course he must tell his father.



CHAPTER XIX

A DISCUSSION

"Come on, Hugh, let's go," exclaimed Bob. Heinrich had turned away from them and walked off angrily. The combination of Lena and Karl and Mr. Wernberg, had been too much for him to stand apparently. He was mad clear through.

"Well," said Bob, when they were outside, "I never would have believed that."

"I told you to watch them all," Hugh reminded him.

"I know you did, and I guess you were right. Why poor old Heinie should be such a fool is more than I can understand."

"Are you going to tell your father?"

"I suppose I must."

"Will he tell the police?"

"I don't know. I should think perhaps he'd have to, though."

"It's too bad," murmured Hugh. He knew how fond his friend was of Heinrich.

"At any rate Karl is all right I guess," said Bob.

"I'll agree with you there," said Hugh. "How about Lena?"

"Don't ask me. I feel as if I couldn't think."

Mr. Cook met them on the front porch and was at once impressed by the expression on the faces of the two boys.

"What's wrong?" he demanded.

"We've just had an awful shock," said Hugh.

"What is it? Tell me, Bob," his father urged.

"Heinrich is one of Mr. Wernberg's gang."

"Say that again," exclaimed Mr. Cook incredulously.

"Heinrich is working with Mr. Wernberg. You ought to see the pile of money he has been paid already."

"Why, Bob," exclaimed Mr. Cook amazedly. "I think you must be mistaken."

"He just told us himself," said Bob. "He said Mr. Wernberg was a fine man and one of the few who knew right from wrong."

"How did he happen to tell you all this?"

Bob related the circumstances to his father. When he had finished Mr. Cook remained silent for several minutes.

"I am so sorry," he said finally. "I don't see why Heinrich told you."

"He was mad," said Bob, "and jealous."

"A dangerous man to hire for that kind of work I should think," exclaimed Mr. Cook. "If he would say as much as he did to you this afternoon I don't see what there is to prevent him from telling all he knows."

"You mean he might give the whole thing away?"

"Exactly."

"Still," said Bob, "Heinie can be awfully stubborn sometimes."

"I know it. We'd have to be clever to get a full confession from him I imagine."

"I don't see what use he could be to Mr. Wernberg," said Hugh.

"It's a favorite method of these German plotters, Hugh," said Mr. Cook. "Very often they get some simple-minded, ignorant fellow like Heinrich and make a tool of him. Heinrich hasn't got brains enough to think of anything himself."

"Are you going to turn him over to the police?" inquired Bob.

"I was just thinking of that," said Mr. Cook. "I certainly would hate to do it."

"But he may do some damage."

"I know it and I think I know what I'll do. To-night I expect to be at the factory practically all night; I'll keep Heinrich with me on one pretext or another. He'll be right with me all the time so that he won't be able to do any harm and besides I can watch his actions. I am still hoping that he may prove to be loyal."

"I'm afraid he won't," said Bob.

"I'm afraid not too," agreed his father. "Still I won't let him out of my sight and when morning comes we can decide what ought to be done about Him."

"If it isn't too late."

"Let's hope not," exclaimed Mr. Cook earnestly.

"Hugh and I would like to help guard the factory to-night," said Bob.

"I think we have plenty of guards," said Mr. Cook. "You'd better stay home and go to bed; you've had a busy time of it the last two days."

"I know it, but we want to help," explained Bob. "Somehow I have a feeling that something is going to happen down there to-night."

"Suppose it does, and you get hurt. What would your mother say?"

"That's what Karl Hoffmann said," exclaimed Hugh.

"Karl is usually right too," said Mr. Cook. "He takes so much responsibility about my personal affairs that really I don't know what I'd do without him."