"That is the heart of America," said Del Mar, earnestly. "It embraces New York, Boston, Philadelphia. But that is not the point. Here are the great majority of the gun and armor factories, the powder and cartridge works, together with the principal coal fields of Pennsylvania."

He brought his fist down decisively on the table. "If we hold this section," he declared, "we practically hold America!"

Eagerly the other emissaries listened as Del Mar laid before them the detailed facts which he was collecting, the greater mission than the mere capture of Kennedy's wireless torpedo which had brought him into the country. Detail after detail of their plans they discussed as they worked out the gigantic scheme.

It was a war council of a secret advance guard of the enemies of America!

. . . . . . .

Meanwhile, Del Mar's man in his boat, cutting a wide circle and avoiding the Dodge boat carrying the naturalist, made his way across the harbor until he came to the shore.

There he landed and proceeded up the beach to the foot of a rocky cliff, where he turned and followed a trail up it to the top. It was the same path already travelled by my captors with me and later followed by Elaine.

As he came stealthily out from under cover, Del Mar's man gazed down the stairway. He drew back at what he saw. Slowly he pulled a gun from his pocket, watching down the steps with tense interest. There he could see Elaine and myself wearily climbing toward the top, our backs toward him, as we covered the men in the cave.

So surprised was he at what he saw that he forgot that his boat below had been followed by the mysterious naturalist, who, the moment Del Mar's man had landed, put on the last burst of speed and ran the Dodge boat close to the spot where the aide had left Del Mar's.

A glance into the boat sufficed to tell the naturalist that the figure in it was only a dummy. He did not pause, but followed the trail up the hill, until he was close after the emissary ahead, going more slowly.

Only a few feet further along the cliff, the naturalist paused, too, keeping well under cover, for the man was now just ahead of him. He looked fixedly at him and saw him gaze down the cliff. Then he saw him slowly draw a gun.

Who could be below? Quickly the naturalist's mind seemed to work. He crouched down, as if ready to spring.

The emissary slowly raised his revolver and took careful aim at the backs of Elaine and myself, as we came up the steps.

But before he could pull the trigger, the naturalist, more like one of the wild animals which he studied than like a human being, sprang from his concealment in the bushes and pounced on the man from behind, seizing him firmly.

Over and over they rolled, struggling almost to the brink of the precipice.

Elaine and I had got almost to the top of the flight of steps, when suddenly we heard a shout above us and sounds of a terrific struggle. We turned, to see two men, neither of whom we knew, fighting. One seemed to be a professor of natural history from his dress and general appearance. The other had a sinister nondescript look.

Nearer and nearer the edge of the cliff they rolled. We crouched closer to the rocky wall, gazing up at the death grapple of the two. Who they were we did not know but that one was fighting for and the other against us we could readily see.

The more vicious of the two seemed to be forcing the naturalist slowly back, when, with a superhuman effort, the naturalist braced himself. His foot was actually on a small ledge of rock directly at the edge of the cliff.

He swung around quickly and struck the other man. The vicious looking man pitched headlong over the cliff.

We shrank back closer to the rock as the man hurtled through the air only a few feet from us. Down below, we could hear him land with a sickening thud.

Far over the edge Elaine leaned in a sort of fascination at the awful sight. For a moment, I thought the very imp of the perverse had got possession of her and that she herself would fall over. She brushed her hand unsteadily over her eyes and staggered. I caught her just in time.

It was only an instant before the brave girl recovered control of herself. Then, together, we started again to climb up.

As we did so the naturalist looked down and caught sight of us approaching. Hastily he hid in the bushes. We reached the top of the stairway and gazed about for the victor in the contest. To our surprise he was gone.

"Come," I urged. "We had better get away, quickly."

As Elaine and I disappeared, the naturalist slowly emerged again from the bushes and looked after us. Then he gave a hasty glance over the edge of the cliff at the man, twisted and motionless, far below.

If we had looked back we might have seen the naturalist shake his head in a manner strangely reminiscent as he turned and gazed again after us.



CHAPTER X

THE CONSPIRATORS

"You remember Lieutenant Woodward, the inventor of trodite?" I asked Elaine one day after I had been out for a ride through the country.

"Very well indeed," she nodded with a look of wistfulness as the mention of his name recalled Kennedy. "Why?"

"He's stationed at Fort Dale, not very far from here, at the entrance of the Sound," I answered.

"Then let's have him over at my garden party to-night," she exclaimed, sitting down and writing.

DEAR LIEUTENANT,

I have just learned that you are stationed at Fort Dale and would like to have you meet some of my friends at a little garden party I am holding to-night.

Sincerely, ELAINE DODGE.

Thus it was that a few hours afterward, in the officers' quarters at the Fort, an orderly entered with the mail and handed a letter to Lieutenant Woodward. He opened it and read the invitation with pleasure. He had scarcely finished reading and was hastening to write a reply when the orderly entered again and saluted.

"A Professor Arnold to see you, Lieutenant," he announced.

"Professor Arnold?" repeated Woodward. "I don't know any Professor Arnold. Well, show him in, anyhow."

The orderly ushered in a well-dressed man with a dark, heavy beard and large horn spectacles. Woodward eyed him curiously and a bit suspiciously, as the stranger seated himself and made a few remarks.

The moment the orderly left the room, however, the professor lowered his voice to a whisper. Woodward listened in amazement, looked at him more closely, then laughed and shook hands cordially.

The professor leaned over again. Whatever it was that he said, it made a great impression on the Lieutenant.

"You know this fellow Del Mar?" asked Professor Arnold finally.

"No," replied Woodward.

"Well, he's hanging around Miss Dodge all the time," went on Arnold. "There's something queer about his presence here at this time."

"I've an invitation to a garden party at her house to-night," remarked Woodward.

"Accept," urged the professor, "and tell her you are bringing a friend."

Woodward resumed writing and when he had finished handed the note to the stranger, who read:

DEAR MISS DODGE,

I shall be charmed to be with you to-night and with your permission will bring my friend, Professor Arnold.

Truly yours, EDWARD WOODWARD.

"Good," nodded the professor, handing the note back.

Woodward summoned an orderly. "See that that is delivered at Dodge Hall to Miss Dodge herself as soon as possible," he directed, as the orderly took the note and saluted.

Elaine, Aunt Josephine and I were in the garden when Lieut. Woodward's orderly rode up and delivered the letter.

Elaine opened it and read. "That's all right," she thanked the orderly. "Oh, Walter, he's coming to the garden party, and is going to bring a friend of his, a Professor Arnold."

We chatted a few moments about the party.

"Oh," exclaimed Elaine suddenly, "I have an idea."

"What is it?" we asked, smiling at her enthusiasm.

"We'll have a fortune teller," she cried. "Aunt Josephine, you shall play the part."

"All right, if you really want me," consented Aunt Josephine smiling indulgently as we urged her.

. . . . . . .

Down in the submarine harbor that afternoon, Del Mar and his men were seated about the conference table.

"I've traced out the course and the landing points of the great Atlantic cable," he said. "We must cut it."

Del Mar turned to one of the men. "Take these plans to the captain of the steamer and tell him to get ready," he went on. "Find out and send me word when the cutting can be done best."

The man saluted and went out.

Leaving the submarine harbor in the usual manner, he made his way to a dock on the shore around the promontory and near the village. Tied to it was a small tramp steamer. The man walked down the dock and climbed aboard the boat. There several rough looking sailors were lolling and standing about. The emissary selected the captain, a more than ordinarily tough looking individual.

"Mr. Del Mar sends you the location of the Atlantic cable and the place where he thinks it best to pick it up and cut it," he said.

The captain nodded. "I understand," he replied. "I'll send him word later when it can be done best."

A few minutes after dispatching his messenger, Del Mar left the submarine harbor himself and entered his bungalow by way of the secret entrance. There he went immediately to his desk and picked up the mail that had accumulated in his absence. One letter he read:

DEAR MR. DEL MAR,

We shall be pleased to see you at a little garden party we are holding to-night.

Sincerely,

ELAINE DODGE.

As he finished reading, he pushed the letter carelessly aside as though he had no time for such frivolity. Then an idea seemed to occur to him. He picked it up again and read it over.

"I'll go," he said to himself, simply.

. . . . . . .

That night Dodge Hall was a blaze of lights and life, overflowing to the wide verandas and the garden. Guests in evening clothes were arriving from all parts of the summer colony and were being received by Elaine. Already some of them were dancing on the veranda.

Among the late arrivals were Woodward and his friend, Professor Arnold.

"I'm so glad to know that you are stationed at Fort Dale," greeted Elaine. "I hope it will be for all summer."

"I can't say how long it will be, but I shall make every effort to make it all summer," he replied gallantly. "Let me present my friend, Professor Arnold."

The professor bowed low and unprofessionally over Elaine's hand and a moment later followed Woodward out into the next room as the other guests arrived to be greeted by Elaine. For a moment, however, she looked after him curiously. Once she started to follow as though to speak to him. Just then, however, Del Mar entered.

"Good evening," he interrupted, suavely.

He stood for a moment with Elaine and talked.

One doorway in the house was draped and a tent had been erected in the room. Over the door was a sign which read: "The past and the future are an open book to Ancient Anna." There Aunt Josephine held forth in a most effective disguise as a fortune teller.

Aunt Josephine had always had a curious desire to play the old hag in amateur dramatics and now she had gratified her desire to the utmost. Probably none of the guests knew that Ancient Anna was in reality Elaine's guardian.

Elaine being otherwise occupied, I had selected one of the prettiest of the girls and we were strolling through the house, seeking a quiet spot for a chat.

"Why don't you have your fortune told by Ancient Anna?" laughed my companion as we approached the tent.

"Do you tell a good fortune reasonably?" I joked, entering.

"Only the true fortunes, young man," returned Ancient Anna severely, starting in to read my palm. "You are very much in love," she went on, "but the lady is not in this tent."

Very much embarrassed, I pulled my hand away.

"How shocking!" mocked my companion, making believe to be very much annoyed. "I don't think I'll have my fortune told," she decided as we left the room.

We sauntered along to the veranda where another friend claimed my companion for a dance which she had promised. As I strolled on alone, Del Mar and Elaine were already finishing a dance. He left her a moment later and I hurried over, glad of the opportunity to see her at last.

Del Mar made his way alone among the guests and passed Aunt Josephine disguised as the old hag seated before her tent. Just then a waiter came through with a tray of ices. As he passed, Del Mar stopped him, reached out and took an ice.

Under the ice, as he had known, was a note. He took the note surreptitiously, turned and presented the ice to Ancient Anna with a bow.

"Thank you, kind sir," she curtsied, taking it.

Del Mar stepped aside and glanced at the little slip of paper. Then he crumpled it up and threw it aside, walking away.

No sooner had he gone than Aunt Josephine reached out and picked up the paper. She straightened it and looked at it. There was nothing on the paper but a crude drawing of a sunrise on the ocean.

"What's that?" asked Aunt Josephine, in surprise.

Just then Elaine and Lieutenant Woodward came in and stopped before the tent. Aunt Josephine motioned to Elaine to come in and Elaine followed. Lieutenant Woodward started after her.

"No, no, young man," laughed Ancient Anna, shaking her forefinger at him, "I don't want you. It's the pretty young lady I want."

Woodward stood outside, though he did not know quite what it was all about. While he was standing there, Professor Arnold came up. He had not exactly made a hit with the guests. At least, he seemed to make little effort to do so. He and Woodward walked away, talking earnestly.

In the tent Aunt Josephine handed Elaine the piece of paper she had picked up.

"What does it mean?" asked Elaine, studying the curious drawing in surprise.

"I'm sure I don't know," confessed Aunt Josephine.

"Nor I."

Meanwhile Lieutenant Woodward and his friend had moved to a corner of the veranda and stood looking intently into the moonlight. There was Del Mar deep in conversation with a man who had slipped out, at a quiet signal, from his hiding-place in the shrubbery.

"That fellow is up to something, mark my words," muttered Arnold under his breath. "I'd like to make an arrest, but I've got to have some proof."

They continued watching Del Mar but, so far at least, he did nothing that would have furnished them any evidence of anything.

So the party went on, most merrily until, long after the guests had left, Elaine sat in her dressing-gown up in her room, about to retire.

Her maid had left her and she picked up the slip of paper from her dresser, looking at it thoughtfully.

"What can a crude drawing of a sunrise on the sea mean?" she asked herself.

For a long time she studied the paper, thinking it over. At last an idea came to her.

"I'll bet I have it," she exclaimed to herself. "Something is going to happen on the water at sunrise."

She took a pretty little alarm clock from the table, set it, and placed it near her bed.

Returning from the party to his library, Del Mar entered. Except for the moonlight streaming in through the windows the room was dark. He turned on the lights and crossed to the panel in the wall. As he touched a button the panel opened. Del Mar switched off the lights and went through the panel, closing it.

Outside, at the other end of the passageway, was one of his men, waiting in the shadows as Del Mar came up. For a moment they talked. "I'll be there, at sunrise," agreed Del Mar, as the man left and he reentered the secret passage.

While he was conferring, at the library window appeared a face. It was Professor Arnold's. Cautiously he opened the window and listened. Then he entered.

First he went over to the door and set a chair under the knob. Next he drew an electric pocket bull's-eye and flashed it about the room. He glanced about and finally went over to Del Mar's desk where he examined a batch of letters, his back to the secret panel.

Arnold was running rapidly through the papers on the desk, as he flashed his electric bull's-eye on them, when the panel in the wall opened slowly and Del Mar stepped into the room noiselessly. To his surprise he saw a round spot of light from an electric flashlight focussed on his desk. Some one was there! He drew a gun.

Arnold started suddenly. He heard the cocking of a revolver. But he did not look around. He merely thought an instant, quicker than lightning, then pulled out a spool of black thread with one hand, while with the other he switched off the light, and dived down on his stomach on the floor in the shadow.

"Who's that?" demanded Del Mar. "Confound it! I should have fired at sight."

The room was so dark now that it was impossible to see Arnold. Del Mar gazed intently. Suddenly Arnold's electric torch glowed forth in a spot across the room.

Del Mar blazed at it, firing every chamber of his revolver, then switched on the lights.

No one was in the room. But the door was open. Del Mar gazed about, vexed, then ran to the open door.

For a second or two he peered out in rage, finally turning back into the empty room. On the mantlepiece lay the torch of the intruder. It was one in which the connection is made by a ring falling on a piece of metal. The ring had been left up by Arnold. Connection had been made as he was leaving the room by pulling the thread which he had fastened to the ring. Del Mar followed the thread as it led around the room to the doorway.

"Curse him!" swore Del Mar, smashing down the innocent torch on the floor in fury, as he rushed to the desk and saw his papers all disturbed.

Outside, Arnold had made good his escape. He paused in the moonlight and listened. No one was pursuing. He drew out two or three of the letters which he had taken from Del Mar's desk, and hastily ran through them.

"Not a thing in them," he exclaimed, tearing them up in disgust and hurrying away.

At the first break of dawn the little alarm dock awakened Elaine. She started up and rubbed her eyes at the suddenness of the awakening, then quickly reached out and stopped the bell so that it would not disturb others in the house. She jumped out of bed hurriedly and dressed.

Armed with a spy glass, Elaine let herself out of the house quietly. Directly to the shore she went, walking along the beach. Suddenly she paused. There were three men. Before she could level her glass at them, however, they disappeared.

"That's strange," she said to herself, looking through the glass. "There's a steamer at the dock that seems to be getting ready for something. I wonder what it can be doing so early."

She moved along in the direction of the dock. At the dock the disreputable steamer to which Del Mar had dispatched his emissary was still tied, the sailors now working under the gruff orders of the rough captain. About a capstan were wound the turns of a long wire rope at the end of which was a three-pronged drag-hook.

"You see," the captain was explaining, "we'll lower this hook and drag it along the bottom. When it catches anything we'll just pull it up. I have the location of the cable. It ought to be easy to grapple."

Already, on the shore, at an old deserted shack of a fisherman, two of Del Mar's men had been waiting since before sun-up, having come in a dirty, dingy fishing smack anchored offshore.

"Is everything ready?" asked Del Mar, coming up.

"Everything, sir," returned the two, following him along the shore.

"Who's that?" cautioned one of the men, looking ahead.

They hid hastily, for there was Elaine. She had seen the three and was about to level her glass in their direction as they hid. Finally she turned and discovered the steamer. As she moved toward it, Del Mar and the others came out from behind a rock and stole after her.

Elaine wandered on until she came to the dock. No one paid any attention to her, apparently, and she made her way along the dock and even aboard the boat without being observed.

No sooner had she got on the boat, however, than Del Mar and his men appeared on the dock and also boarded the steamer.

The captain was still explaining to the men just how the drag-hook worked when Elaine came up quietly on the deck. She stood spellbound as she heard him outline the details of the plot. Scarcely knowing what she did, she crouched back of a deckhouse and listened.

Behind her, Del Mar and his men came along, cat-like. A glance was sufficient to tell them that she had overheard what the captain was saying.

"Confound that girl!" ground out Del Mar. "Will she always cross my path? We'll get her this time!"

The men scattered as he directed them. Sneaking up quietly, they made a sudden rush and seized her. As she struggled and screamed, they dragged her off. thrusting her into the captain's cabin and locking the door.

"Cast off!" ordered Del Mar.

A few moments later, out in the harbor, Del Mar was busy directing the dragging for the Atlantic cable at a spot where it was known to run. They let the drag-hook down over the side and pulled it along slowly on the bottom.

In the cabin, Elaine beat on the door and shouted in vain for help.

I had decided to do some early morning fishing the day after the party, and knowing that Elaine and the others were usually late risers, I said nothing about it, determined to try my luck alone.

So it happened that only a few minutes after Elaine let herself out quietly, I did the same, carrying my fishing-tackle. I made my way toward the shore, undecided whether to fish from a dock or boat. Finally I determined to do some casting from the shore.

I had cast once or twice before I was aware that I was not alone in the immediate neighborhood. Some distance away I saw a little steamer at a wharf. A couple of men ran along the deck, apparently cautioning the captain against something.

Then I saw them run to one side and drag out a girl, screaming and struggling as they hurried her below. I could scarcely believe my eyes. It was Elaine!

Only a second I looked. They were certainly too many for me. I dropped my rod and line and ran toward the dock, however. As I came down it, I saw that I was too late. The little steamer had cast off and was now some distance from the dock. I looked about for a motor-boat in desperation—anything to follow them in. But there was nothing, absolutely nothing, not even a rowboat.

I ran back along the dock as I had come and struck out down the shore.

. . . . . . .

Out at the parade grounds at Fort Dale, in spite of the early hour, there was some activity, for the army is composed of early risers.

Lieutenant Woodward and Professor Arnold left the house in which the Lieutenant was quartered, where he had invited Arnold to spend the night. Already an orderly had brought around two horses. They mounted for an early morning ride through the country.

Off they clattered, naturally bending their course toward the shore. They came soon to a point in the road where it emerged from the hills and gave them a panoramic view of the harbor and sound.

"Wait a minute," called the professor.

Woodward reined up and they gazed off over the water.

"What's that—an oyster boat?" asked Woodward, looking in the direction Arnold indicated.

"I don't think so, so early," replied Arnold, pulling out his pocket glass and looking carefully.

Through it he could see that something like a hook was being cast over the steamer's side and drawn back again.

"They're dragging for something," he remarked as they brought up an object dark and covered with seagrowth, then threw it overboard as though it was not what they wanted. "By George—the Atlantic cable lands here—they're going to cut it!"

Woodward took the glasses himself and looked in in surprise. "That's right," he cried, his surprise changed to alarm in an instant. "Here, take the glass again and watch. I must get back to the Fort."

He swung his horse about and galloped off, leaving Arnold sitting in the saddle gazing at the strange boat through his glass.

By the time Woodward reached the parade ground again, a field-gun and its company were at drill. He dashed furiously across the field.

"What's the trouble?" demanded the officer in charge of the gun.

Woodward blurted out what he had just seen. "We must stop it—at any cost," he added, breathlessly.

The officer turned to the company. A moment later the order to follow Woodward rang out, the horses were wheeled about, and off the party galloped. On they went, along the road which Woodward and Arnold had already traversed.

Arnold was still gazing, impatiently now, through the glass. He could see the fore-deck of the ship where Del Mar, muffled up, and his men had succeeded in dragging the cable to the proper position on the deck. They laid it down and Del Mar was directing the preparations for cutting it. Arnold lowered his glass and looked about helplessly.

Just then Lieutenant Woodward dashed up with the officer and company and the field-gun. They wheeled it about and began pointing it and finding the range.

Would they never get it? Arnold was almost beside himself. One of Del Mar's men seized an axe and was about to deliver the fatal blow. He swung it and for a moment held it poised over his head.

Suddenly a low, deep rumble of a reverberation echoed and reechoed from the hills over the water. The field-gun had bellowed defiance.

A solid shot crashed through the cabin, smashing the door. Astounded, the men jumped back. As they did so, in their fear, the cable, released, slipped back over the rail in a great splash of safety into the water and sank.

"The deuce take you—you fools," swore Del Mar, springing forward in rage, and looking furiously toward the shore.

Two of the men had been hit by splinters. It was impossible to drag again. Besides, again the gun crew loaded and fired.

The first shot had dismantled the doorway of the cabin. Elaine crouched fearfully in the furthest corner, not knowing what to expect next. Suddenly another shot tore through just beside the door, smashing the woodwork terrifically. She shrank back further, in fright.

Anything was better than this hidden terror. Nerved up, she ran through the broken door.

Arnold was gazing through his glass at the effect of the shots. He could now see Del Mar and the others leaping into a swift little motor-boat alongside the steamer which they had been using to help them in dragging for the cable.

Just then he saw Elaine run, screaming, out from the cabin and leap overboard.

"Stop!" shouted Arnold in a fever of excitement, lowering his glass. "There's a girl—by Jove—it's Miss Dodge!"

"Impossible!" exclaimed Woodward.

"I tell you, it is," reiterated Arnold, thrusting the glass into the Lieutenant's hand.

The motor-boat had started when Del Mar saw Elaine in the water. "Look," he growled, pointing, "There's the Dodge girl."

Elaine was swimming frantically away from the boat. "Get her," he ordered, shielding his face so that she could not see it.

They turned the boat and headed toward her. She struck out harder than ever for the shore. On came the motor-boat.

Arnold and Woodward looked at each other in despair. What could they do?

. . . . . . .

Somehow, by a sort of instinct, I suppose, I made my way as quickly as I could along the shore toward Fort Dale, thinking perhaps of Lieutenant Woodward.

As I came upon the part of the grounds of the Fort that sloped down to the beach, I saw a group of young officers standing about a peculiar affair on the shore in the shallow water—half bird, half boat.

As I came closer, I recognized it as a Thomas hydroaeroplane.

It suggested an idea and I hurried, shouting.

One of the men, seated in it, was evidently explaining its working to the others.

"Wait," he said, as he saw me running down the shore, waving and shouting at them. "Let's see what this fellow wants."

It was, as I soon learned, the famous Captain Burnside, of the United States Aerial Corps. Breathless, I told him what I had seen and that we were all friends of Woodward's.

Burnside thought a moment, and quickly made up his mind.

"Come—quick—jump up here with me," he called. Then to the other men, "I'll be back soon. Wait here. Let her go!"

I had jumped up and they spun the propeller. The hydroaeroplane feathered along the water, throwing a cloud of white spray, then slowly rose in the air.

The sensation of flying was delightful, as the fresh morning wind cut our faces. We seemed to be hardly moving. It was the earth or rather the water that rushed past under us. But I forgot all about my sensations in my anxiety for Elaine.

As we rose we could see over the curve in the shore.

"Look!" I exclaimed, straining my eyes. "She's overboard. There's a motor-boat after her. Faster—over that way!"

"Yes, yes," shouted Burnside above the roar of the engine which almost made conversation impossible.

He shifted the planes a bit and crowded on more speed.

The men in the boat saw us. One figure, tall, muffled, had a familiar look, but I could not place it and in the excitement of the chase had no chance to try. But I could see that he saw us and was angry. Apparently the man gave orders to turn, for the boat swung around just as we swooped down and ran along the water.

Elaine was exhausted. Would we be in time?

We planed along the water, while the motor-boat sped off with its baffled passengers. Finally we stopped, in a cloud of spray.

Together, Burnside and I reached down and caught Elaine, not a moment too soon, dragging her into the boat of the hydroaeroplane.

If we had not had all we could do, we might have heard a shout of encouragement and relief from the hill where Woodward and Arnold and the rest were watching anxiously.

I threw my coat about her, as the brave girl heroically clung to us, half conscious.

"Oh—Walter," she murmured, "you were just in time."

"I wish I could have been sooner," I apologized.

"They—they didn't cut the cable—did they?" she asked, as we rose from the water again, bearing her now to safety. "I did my best."



CHAPTER XI

THE WIRELESS DETECTIVE

Del Mar made his way cautiously along the bank of a little river at the mouth of which he left the boat after escaping from the little steamer.

Quite evidently he was worried by the failure to cut the great Atlantic cable and he was eager to see whether any leak had occurred in the organization which, as secret foreign agent, he had so carefully built up in America.

As he skirted the shore of the river, he came to a falls. Here he moved even more cautiously than before, looking about to make certain that no one had followed him.

It was a beautiful sheet of water that tumbled with a roar over the ledge of rock, then raced away swiftly to the sea in a cloud of spray.

Assured that he was alone, he approached a crevice in the rocks, near the falls. With another hasty look about, he reached in and pulled a lever.

Instantly a most marvellous change took place, incredible almost beyond belief. The volume of water that came over the falls actually and rapidly decreased until it almost stopped, dripping slowly in a thin veil. There was the entrance of a cave—literally hidden behind the falls!

Del Mar walked in. Inside was the entrance to another, inner cave, higher up in the sheer stone of the wall that the waters had eroded. From the floor to this entrance led a ladder. Del Mar climbed it, then stopped just inside the entrance to the inner cave. For a moment he paused. Then he pressed another lever. Almost immediately the thin trickle of water grew until at last the roaring falls completely covered the cave entrance. It was a clever concealment, contrived by damming the river above and arranging a new outlet controlled by flood-gates.

There Del Mar stood, in the inner cave. A man sat at a table, a curious gear fastened over his head and covering his ears. Before him was a huge apparatus from which flared a big bluish-green spark, snapping and crackling above the thunder of the waves. From the apparatus ran wires apparently up through cables that penetrated the rocky roof of the cavern and the river above.

It was Del Mar's secret wireless station, close to the hidden submarine harbor which had been established beneath the innocent rocks of the promontory up the coast. Far overhead, on the cliff over the falls, were the antennae of the wireless.

"How is she working?" asked Del Mar.

"Pretty well," answered the man.

"No interference?" queried Del Mar, adjusting the apparatus.

The man shook his head in the negative.

"We must get a quenched spark apparatus," went on Del Mar, pleased that nothing was wrong here. "This rotary gap affair is out of date. By the way, I want you to be ready to send a message, to be relayed across to our people. I've got to consult the board below in the harbor, first, however. I'll send a messenger to you."

"Very well, sir," returned the man, saluting as Del Mar went out.

Out at Fort Dale, Lieutenant Woodward was still entertaining his new friend, Professor Arnold, and had introduced him to Colonel Swift, the commanding officer at the Fort.

They were discussing the strange events of the early morning, when an orderly entered, saluted Colonel Swift and handed him a telegram. The Colonel tore it open and read it, his face growing grave. Then he handed it to Woodward, who read:

WASHINGTON, D. C.

Radio station using illegal wave length in your vicinity. Investigate and report.

BRANDON,

Radio Bureau.

Professor Arnold shook his head slowly, as he handed the telegram back. "There's a wireless apparatus of my own on my yacht," he remarked slowly. "I have an instrument there which I think can help you greatly. Let's see what we can do."

"All right," nodded Colonel Swift to Woodward. "Try."

The two went out and a few minutes later, on the shore, jumped into Arnold's fast little motor-boat and sped out across the water until they swung around alongside the trim yacht which Arnold was using.

It was a compact and comfortable little craft with lines that indicated both gracefulness and speed. On one of the masts, as they approached, Woodward noticed the wireless aerial. They climbed up the ladder over the side and made their way directly to the wireless room, where Arnold sat down and at once began to adjust the apparatus.

Woodward seemed keenly interested in inspecting the plant which was of a curious type and not exactly like any that he had seen before.

"Wireless apparatus," explained Arnold, still at work, "as you know, is divided into three parts, the source of power, the making and sending of wireless waves, including the key, spark, condenser and tuning coil, and the receiving apparatus—head telephones, antennae, ground and detector. This is a very compact system with facilities for a quick change from one wave length to another. It has a spark gap, quenched type, break system relay—operator can hear any interference while transmitting—transformation by a single throw of a six-point switch which tunes the oscillating and open circuits to resonance."

Woodward watched him keenly, following his explanation carefully, as Arnold concluded.

"You might call it a radio detective," he added.

Even the startling experience of the morning when she was carried off and finally jumped from the little tramp steamer that had attempted to cut the cable did not dampen Elaine's ardor. She missed the guiding hand of Kennedy, yet felt impelled to follow up and investigate the strange things that had been happening in the neighborhood of her summer home since his disappearance.

I succeeded in getting her safely home after Burnside and I rescued her in the hydroaeroplane, but no sooner had she changed her clothes for dry ones than she disappeared herself. At least I could not find her, though, later, I found that she had stolen away to town and there had purchased a complete outfit of men's clothes from a second hand dealer.

Cautiously, with the large bundle under her arm, she returned to Dodge Hall and almost sneaked into her own home and up-stairs to her room. She locked the door and hastily unwrapped the bundle taking out a tattered suit and the other things, holding them up and laughing gleefully as she took off her own pretty clothes and donned these hideous garments.

Quickly she completed her change of costume and outward character. As she surveyed herself in the dainty mirror of her dressing-table she laughed again at the incongruity of her pretty boudoir and the rough men's clothes she was wearing. Deftly she arranged her hair so that her hat would cover it. She picked a black mustache from the table and stuck it on her soft upper lip. It tickled and she made a wry face over it. Then she hunted up a cigarette from the bundle which she had brought in, lighted it and stuck it in the corner of her mouth, letting it droop jauntily. It made her cough tremendously and she threw it away.

Finally she went to the door and down-stairs. No one was about. She opened the door and gazed around. All was quiet. It was a new role for her, but, with a bold front, she went out and passed down to the gate of the grounds, pulling her hat down over her eyes and assuming a tough swagger.

Only a few minutes before, down in the submarine harbor, the officers of the board of foreign agents had been grouped about Del Mar, who had entered and taken his place at their head, very angry over the failure to cut the cable. As they concluded their hasty conference, he wrote a message on a slip of paper.

"Take this to our wireless station," he ordered, handing it to one of the men.

The man took it, rose, and went to a wardrobe from which he extracted one of the submarine suits. With the message in his hand, he went out of the room, buckling on the suit.

A few minutes later the messenger in the submarine suit bobbed up out of the water, near the promontory, and climbed slowly over the rocks toward a crevice, where he began to take off the diving outfit.

Having finished, he hid the suit among the rocks and then went along to the little river, carefully skirting its banks into the ravine in which were the falls and the wireless cave.

In her disguise, Elaine had made her way by a sort of instinct along the shore to the rocky promontory where we had discovered the message in the tin tube in the water.

Something, she knew not what, was going on about there, and she reasoned that it was not all over yet. She was right. As she looked about keenly she did see something, and she hid among the rocks. It was a man, all dripping, in an outlandish helmet and suit.

She saw him slink into a crevice and take off the suit, then, as he moved toward the river ravine, she stole up after him.

Suddenly she stopped stark still, surprised, and stared.

The man had actually gone up to the very waterfall. He had pressed what looked like a lever and the water over the falls seemed to stop. Then he walked directly through into a cave.

In the greatest wonder, Elaine crept along toward the falls. Inside the cave Del Mar's emissary started to climb a ladder to an inner cave. As he reached the top, he glanced out and saw Elaine by the entrance. With an oath he jumped into the inner entrance. His hand reached eagerly for a lever in the rocks and as he found and held it, he peered out carefully.

Elaine cautiously came from behind a rock where she had hidden herself and seeing no one apparently watching, now, advanced until she stood directly under the trickle of water which had once been the falls. She gazed into the cave, curiously uncertain whether she dared to go in alone or not.

The emissary jerked fiercely at the lever as he saw Elaine.

Above the falls a dam had been built and by a system of levers the gates could be operated so that the water could be thrown over the falls or diverted away, at will. As the man pressed the lever, the flood gates worked quickly.

Elaine stood gazing eagerly into the blackness of the cave. Just then a great volume of water from above crashed down on her, with almost crushing weight.

How she lived through it she never knew. But, fortunately, she had not gone quite far enough to get the full force of the water. Still, the terrific flood easily overcame her.

She was swept, screaming, down the stream.

. . . . . . .

Rather alarmed at the strange disappearance of Elaine after I brought her home, I had started out along the road to the shore to look for her, thinking that she might perhaps have returned there.

As I walked along a young tough—at least at the time I thought it was a young tough, so good was the disguise she had assumed and so well did she carry it off—slouched past me.

What such a character could be doing in the neighborhood I could not see. But he was so noticeably tough that I turned and looked. He kept his eyes averted as if afraid of being recognized.

"Great Caesar," I muttered to myself, "that's a roughneck. This place is sure getting to be a hang-out for gunmen."

I shrugged my shoulders and continued my walk. It was no business of mine. Finding no trace of Elaine, I returned to the house. Aunt Josephine was in the library, alone.

"Where's Elaine?" I asked anxiously.

"I don't know," she replied. "I don't think she's at home." "Well, I can't find her anywhere," I frowned wandering out at a loss what to do, and thrusting my hands deep in my pockets as an aid to thought.

Somehow, I felt, I didn't seem to get on well as a detective without Kennedy. Yet, so far, a kind providence seemed to have watched over us. Was it because we were children—or—I rejected that alternative.

Walking along leisurely I made my way down to the shore. At a bridge that crossed a rather turbulent stream as it tumbled its way toward the sea, I paused and looked at the water reflectively.

Suddenly my vagrant interest was aroused. Up the stream I saw some one struggling in the water and shouting for help as the current carried her along, screaming.

It was Elaine. The hat and mustache of her disguise were gone and her beautiful Titian hair was spread out on the water as it carried her now this way, now that, while she struck out with all her strength to keep afloat. I did not stop to think how or why she was there. I swung over the bridge rail, stripping off my coat, ready to dive. On she came with the swift current to the bridge. As she approached I dived. It was not a minute too soon. In her struggles she had become thoroughly exhausted. She was a good swimmer but the fight with nature was unequal.

I reached her in a second or so and took her hand. Half pulling, half shoving her, I struck out for the shore. We managed to make it together where the current was not quite so strong and climbed safely up a rock.

Elaine sank down, choking and gasping, not unconscious but pretty much all in and exhausted. I looked at her in amazement. She was the tough character I had just seen.

"Why, where in the world did you get those togs?" I queried.

"Never mind my clothes, Walter," she gasped. "Take me home for some dry ones. I have a clue."

She rose, determined to shake off the effects of her recent plunge and went toward the house. As I helped her she related breathlessly what she has just seen.

Meanwhile, back of that wall of water, the wireless operator in the cave was sending the messages which Del Mar's emissary dictated to him, one after another.

. . . . . . .

With the high resistance receiving apparatus over his head, Arnold was listening to the wireless signals that came over his "radio detective" on the yacht, moving the slider back and forth on a sort of tuning coil, as he listened. Woodward stood close beside him.

"As you know," Arnold remarked, "by the use of an aerial, messages may be easily received from any number of stations. Laws, rules, and regulations may be adopted by the government to shut out interlopers and to plug busybody ears, but the greater part of whatever is transmitted by the Hertzian waves can be snatched down by this wireless detective of mine. Here I can sit in my wireless room with this ear-phone clamped over my head drinking in news, plucking the secrets of others from the sky—in other words, this is eavesdropping by a wireless wire-tapper."

"Are you getting anything now?" asked Woodward.

Arnold nodded, as he seized a pencil and started to write. The lieutenant bent forward in tense interest. Finally Arnold read what he had written and with a peculiar, quiet smile handed it over. Woodward read. It was a senseless jumble of dots and dashes of the Morse code but, although he was familiar with the code, he could make nothing out of it.

"It's the Morse code all right," he said, handing it back with a puzzled look, "but it doesn't make any sense."

Arnold smiled again, took the paper, and without a word wrote on it some more. Then he handed it back to Woodward. "An old trick," he said. "Reverse the dots and dashes and see what you get."

Woodward looked at it, as Arnold had reversed it and his face lighted up.

"Harbor successfully mined," he quoted in surprise.

"I'll show you another thing about this radio detective of mine," went on Arnold energetically. "It's not only a wave length measurer, but by a process of my own I can determine approximately the distance between the sending and the receiving points of a message."

He attached another, smaller machine to the wireless detector. In the face was a moving finger which swung over a dial marked off in miles from one upward. As Arnold adjusted the new detector, the hand began to move slowly. Woodward looked eagerly. It did not move far, but came to rest above the figure "2."

"Not so very far away, you see, Lieutenant," remarked Arnold, pointing at the dial face.

He seized his glass and hurried to the deck, levelling it at the shore, leaning far over the rail in his eagerness. As he swept the shore, he stopped suddenly. There was a house-roof among the trees with a wireless aerial fastened to the chimney, but not quite concealed by the dense foliage.

"Look," he cried to Woodward, with an exclamation of satisfaction, handing over the glass.

Woodward looked. "A secret wireless station, all right," he agreed, lowering the glass after a long look.

"We'd better get over there right away," planned Arnold, leading the way to the ladder over the side of the yacht and calling to the sailor who had managed the little motor-boat to follow him.

Quickly they skimmed across to the shore. "I think we'd better send to the Fort for some men," considered Arnold as they landed. "We may need reinforcements before we get through."

Woodward nodded and Arnold hastily wrote a note on a rather large scrap of paper which he happened to have in his pocket.

"Take this to Colonel Swift at Fort Dale," he directed the sailor. "And hurry!"

The sailor loped off, half on a run, as Arnold and Woodward left down the shore, proceeding carefully.

At top speed, Arnold's sailor made his way to Fort Dale and was directed by the sentry to Colonel Swift who was standing before the headquarters with several officers.

"A message from Lieutenant Woodward and Professor Arnold," he announced, approaching the commanding officer and handing him the note. Colonel Swift tore it open and read:

Have located radio aerial in the woods along shore. Please send squad of men with bearer.—ARNOLD.

"You just left them?" queried the Colonel.

"Yes sir," replied the sailor. "We came ashore in his boat. I don't know exactly where they went but I know the direction and we can catch up with them easily if we hurry, sir."

The colonel handed the note quickly to a cavalry officer beside him who read it, saluted at the orders that followed, turned and strode off, hastily stuffing the paper in his belt, as the sailor went, too.

Meanwhile, Del Mar's valet was leaving the bungalow and walking down the road on an errand for his master. Up the road he heard the clatter of hoofs. He stepped back off the road and from his covert he could see a squad of cavalry headed by the captain and a sailor cantering past.

The captain turned in the saddle to speak to the sailor, who rode like a horse marine, and as he did so, the turning of his body loosened a paper which he had stuffed quickly into his belt. It fell to the ground. In their hurry the troop, close behind, rode over it. But it did not escape the quick eye of Del Mar's valet.

They had scarcely disappeared around a bend in the road when he stepped out and pounced on the paper, reading it eagerly. Every line of his face showed fear as he turned and ran back to the bungalow.

"See what I found," he cried breathlessly bursting in on Del Mar who was seated at his desk, having returned from the harbor.

Del Mar read it with a scowl of fury. Then he seized his hat, and a short hunter's axe, and disappeared through the panel into the subterranean passage which took him by the shortest cut through the very hill to the shore.

Slowly Arnold and Woodward made their way along the shore, carefully searching for the spot where they had seen the house with the aerial. At last they came to a place where they could see the deserted house, far up on the side of a ravine above a river and a waterfalls. They dived into the thick underbrush for cover and went up the hill.

Some distance off from the house, they parted the bushes and gazed off across an open space at the ramshackle building. As they looked they could see a man hurry across from the opposite direction and into the house.

"As I live, I think that's Del Mar," muttered Arnold.

Woodward nodded, doubtfully, though.

In the house, Del Mar hurried to a wall where he found and pressed a concealed spring. A small cabinet in the plaster opened and he took out a little telephone which he rang and through which he spoke hastily. "Pull in the wires," he shouted. "We're discovered, I think."

Down in the wireless station in the cave, the operator at his instrument heard the signal of the telephone and quickly answered it. "All right, sir," he returned with a look of great excitement and anxiety. "Cut the wires and I'll pull them in."

Putting back the telephone, Del Mar ran to the window and looked out between the broken slats of the closed blinds. "Confound them!" he muttered angrily.

He could see Arnold and Woodward cautiously approaching. A moment later he stepped back and pulled a silk mask over his upper face, leaving only his eyes visible. Then he seized his hunter's axe and dashed up the stairs. Through the scuttle of the roof he came, making his way over to the chimney to which the wireless antennae were fastened.

Hastily he cut the wires which ran through the roof from the aerial. As he did so he saw them disappear through the roof. Below, in the cave, down in the ravine back of the falls, the operator was hastily hauling in the wire Del Mar had cut.

Viciously next, Del Mar fell upon the wooden aerial itself, chopping it right and left with powerful blows. He broke it off and threw it over the roof.

Below, Arnold and Woodward, taking advantage of every tree and shrub for concealment, had almost reached the house when the broken aerial fell with a bang almost on them. In surprise they dropped back of a tree and looked up. But from their position they could see nothing. Together they drew their guns and advanced more cautiously at the house.

Del Mar made his way back quickly over the roof, back through the scuttle and down the stairs again. Should he go out? He looked out of the window. Then he went to the door. An instant he paused thinking and listening, his axe raised, ready for a blow.

Arnold and Woodward, by this time, had reached the door which swung open on its rusty hinges. Woodward was about to go in when he felt a hand on his arm.

"Wait," cautioned Arnold. He took off his hat and jammed it on the end of a stick. Slowly he shoved the door open, then thrust the hat and stick just a fraction of a foot forward.

Del Mar, waiting, alert, saw the door open and a hat. He struck at it hard with the axe and merely the hat and stick fell to the floor.

"Now, come on," shouted Arnold to Woodward.

In the other hand, Del Mar held a chair. As Woodward dashed in with Arnold beside him, Del Mar shied the chair at their feet. Woodward fell over it in a heap and as he did so the delay was all that Del Mar had hoped to gain. Without a second's hesitation he dived through an open window, just as Arnold ran forward, avoiding Woodward and the chair. It was spectacular, but it worked. Arnold fired, but even that was not quick enough. He turned and with Woodward who had picked himself up in spite of his barked shins and they ran back through the door by which they had entered.

Recovering himself, Del Mar dashed for the woods just as Arnold and Woodward ran around the side of the house, still blazing away after him, as they followed, rapidly gaining.

Elaine changed her clothes quickly. Meanwhile she had ordered horses for both of us and a groom brought them around from the stables. It took me only a short time to jump into some dry things and I waited impatiently.

She was ready very soon, however, and we mounted and cantered off, again in the direction of the shore where she had seen the remarkable waterfall, of which she had told me.

We had not gone far when we heard sounds, as if an army were bearing down on us. "What's that?" I asked.

Elaine turned and looked. It was a squad of cavalry.

"Why, it's Lieutenant Woodward's friend, Captain Price," she exclaimed, waving to the captain at the head of the squad.

A moment later Captain Price pulled up and bowed. Quickly we told him of what Elaine had just discovered.

"That's strange," he said. "This man—" indicating the sailor— "has just told me that Lieutenant Woodward and Professor Arnold are investigating a wireless outfit over near there. Perhaps there's some connection."

"May we join you?" she asked.

"By all means," he returned. "I was about to suggest it myself."

We fell in behind with the rest and were off again.

Under the direction of the sailor we came at last to the ravine where we looked about searchingly for some trace of Arnold and Woodward.

"What's that noise?" exclaimed one of the cavalrymen.

We could hear shots, above us.

"They may need us," cried Elaine, impatiently.

It was impossible to ride up the sheer height above.

"Dismount," ordered Captain Price.

His men jumped down and we followed him. Elaine struggled up, now helped by me, now helping me.

Further down the hill from the deserted house which we could see above us at the top was an underground passage which had been built to divert part of the water above the falls for power. Through it the water surged and over this boiling stream ran a board walk, the length of the tunnel.

Into this tunnel we could see that a masked man had made his way. As he did so, he turned for just a moment and fired a volley of shots.

Elaine screamed. There were Arnold and Woodward, his targets, coming on boldly, as yet unhit. They rushed in after him, in spite of his running fire, returning his shots and darting toward the tunnel entrance through which he still blazed back at them.

From our end of the ravine, we could see precisely what was going on. "Come—the other end of the tunnel," shouted Price, who had evidently been over the ground and knew it.

We made our way quickly to it and it seemed as if we had our man trapped, like a rat in a hole.

In the tunnel the man was firing back at his pursuers as he ran along the board walk for our end. He looked up just in time as he approached us. There he could see Price and his cavalry waiting, cutting off retreat. We were too many for him. He turned and took a step back. There were Arnold and Woodward with levelled guns peering in as though they could not see very clearly. In a moment their eyes would become accustomed as his to the darkness. What should he do? There was not a second to waste. He looked down at the planks beneath him and the black water slipping past on its way to the power station. It was a desperate chance. But it was all that was left. He dropped down and let himself without even a splash into the water.

Arnold and Woodward took a step into the darkness, scarcely knowing what to expect, their eyes a bit better accustomed to the dusk. But if they had been there an hour, in all probability they could not have seen what was at their very feet.

Del Mar had sunk and was swimming under water in the swift black current sweeping under them. As they entered, he passed out, nerved up to desperation.

Down the stream, just before it took its final plunge to the power wheel, Del Mar managed by a superhuman effort to reach out and grasp a wooden support of the flooring again and pull himself out of the stream. Smiling grimly to himself, he hurried up the bank.

"Some one's coming," whispered Price. "Get ready."

We levelled our guns. I was about to fire.

"Look out! Don't shoot!" warned a voice sharply. It was Elaine. Her keen eyes and quick perception had recognized Arnold, leading Woodward. We lowered our guns.

"Did you see a man, masked, come out here?" cried Woodward.

"No—he must have gone your way," we called.

"No, he couldn't."

Arnold was eagerly questioning the captain as Elaine and I approached. "Dropped into the water—risked almost certain death," he muttered, half turning and seeing us.

"I want to congratulate you on your nerve for going in there," began Elaine, advancing toward the professor.

Apparently he neither heard nor saw us, for he turned as soon as he had finished with Price and went into the cave as though he were too busy to pay any attention to anything else.

Elaine looked up at me, in blank astonishment.

"What an impolite man," she murmured, gazing at the figure all stooped over as it disappeared in the darkness of the tunnel.



CHAPTER XII

THE DEATH CLOUD

Off a lonely wharf in a deserted part of the coast some miles from the promontory which afforded Del Mar his secret submarine harbor, a ship was riding at anchor.

On the wharf a group of men, husky lascars, were straining their eyes at the mysterious craft.

"Here she comes," muttered one of the men, "at last."

From the ship a large yawl had put out. As she approached the wharf it could be seen that she was loaded to the gunwales with cases and boxes. She drew up close to the wharf and the men fell to unloading her, lifting up the boxes as though they were weighted with feathers instead of metal and explosives.

Down the shore, at the same time, behind a huge rock, crouched a rough looking tramp. His interest in the yawl and its cargo was even keener than that of the lascars.

"Supplies," he muttered, moving back cautiously and up the bluff. "I wonder where they are taking them?"

Marcus Del Mar had chosen an old and ruined hotel not far from the shore as his storehouse and arsenal. Already he was there, pacing up and down the rotted veranda which shook under his weight.

"Come, hurry up," he called impatiently as the first of the men carrying a huge box on his back made his appearance up the hill.

One after another they trooped in and Del Mar led them to the hotel, unlocking the door.

Inside, the old hostelry was quite as ramshackle as outside. What had once been the dining-room now held nothing but a long, rickety table and several chairs.

"Put them there," ordered Del Mar, directing the disposal of the cases. "Then you can begin work. I shall be back soon."

He went out and as he did so, two men seized guns from a corner near-by and followed him. On the veranda he paused and turned to the men.

"If any one approaches the house—any one, you understand—make him a prisoner and send for me," he ordered. "If he resists, shoot."

"Yes, sir," they replied, moving over and stationing themselves one at each angle of the narrow paths that ran before the old house.

Del Mar turned and plunged deliberately into the bushes, as if for a cross country walk, unobserved.

Meanwhile, by another path up the bluff, the tramp had made his way parallel to the line taken by the men. He paused at the top of the bluff where some bushes overhung and parted them.

"Their headquarters," he remarked to himself, under his breath.

Elaine, Aunt Josephine and I were on the lawn that forenoon when a groom in resplendent livery came up to us.

"Miss Elaine Dodge?" he bowed.

Elaine took the note he offered and he departed with another bow.

"Oh, isn't that delightful," she cried with pleasure, handing the note to me.

I read it: "The Wilkeshire Country Club will be honored if Miss Dodge and her friends will join the paper chase this afternoon. L.H. Brown, Secretary."

"I suppose a preparation for the fox or drag hunting season?" I queried.

"Yes," she replied. "Will you go?"

"I don't ride very well," I answered, "but I'll go."

"Oh, and here's Mr. Del Mar," she added, turning. "You'll join us at the Wilkeshire hunt in a paper chase this afternoon, surely, Mr. Del Mar?"

"Charmed, I'm sure," he agreed gracefully.

For several minutes we chatted, planning, then he withdrew. "I shall meet you on the way to the Club," he promised.

It was not long before Elaine was ready, and from the stable a groom led three of the best trained cross-country horses in the neighborhood, for old Taylor Dodge, Elaine's father, had been passionately fond of hunting, as had been both Elaine and Aunt Josephine.

We met on the porch and a few minutes later mounted and cantered away. On the road Del Mar joined us and we galloped along to the Hunt Club, careful, however, to save the horses as much as possible for the dash over the fields.

. . . . . . .

For some time the uncouth tramp continued gazing fixedly out of the bushes at the deserted hotel.

Suddenly, he heard a noise and dropped flat on the ground, looking keenly about. Through the trees he could see one of Del Mar's men stationed on sentry duty. He was leaning against a tree, on the alert.

The tramp rose cautiously and moved off in another direction to that in which he had been making his way, endeavoring to flank the sentry. Further along, however, another of Del Mar's men was standing in the same attentive manner near a path that led from the woods.

As the tramp approached, the sentry heard a crackle of the brush and stepped forward. Before the tramp knew it, he was covered by a rifle from the sentry in an unexpected quarter.

Any one but the sentry, with half an eye, might have seen that the fear he showed was cleverly feigned. He threw his hands above his head even before he was ordered and in general was the most tractable captive imaginable. The sentry blew a whistle, whereat the other sentry ran in.

"What shall we do with him," asked the captor.

"Master's orders to take any one to the rendezvous," responded the other firmly, "and lock him up."

Together they forced the tramp to march double quick toward the old hotel. One sentry dropped back at the door and the other drove the tramp before him into the hotel, avoiding the big room on the side where the men were at work and forcing him up-stairs to the attic which had once been the servant's quarters.

There was no window in the room and it was empty. The only light came in through a skylight in the roof.

The sentry thrust the tramp into this room and tried a door leading to the next room. It was locked. At the point of his gun the sentry frisked the tramp for weapons, but found none. As he did so the tramp trembled mightily. But no sooner had the sentry gone than the tramp smiled quietly to himself. He tried both doors. They were locked. Then he looked at the skylight and meditated.

Down below, although he did not know it, in the bare dining-room which had been arranged into a sort of chemical laboratory, Del Mar's men were engaged in manufacturing gas bombs much like those used in the war in Europe. Before them was a formidable array of bottles and retorts. The containers for the bombs were large and very brittle globes of hard rubber. As the men made the gas and forced it under tremendous pressure into tubes, they protected themselves by wearing goggles for the eyes and large masks of cloth and saturated cotton over their mouths and noses.

Satisfied with the safety of his captive, the sentry made his way down-stairs and out again to report to Del Mar.

At the bungalow, Del Mar's valet was setting the library in order when he heard a signal in the secret passage. He pressed the button on the desk and opened the panel. From it the sentry entered.

"Where is Mr. Del Mar?" he asked hurriedly, looking around. "We've been followed to the headquarters by a tramp whom I've captured, and I don't know what to do with him."

"He is not here," answered the valet. "He has gone to the Country Club."

"Confound it," returned the sentry, vexed at the enforced waste of time. "Do you think you can reach him?"

"If I hurry, I may," nodded the valet.

"Then do so," directed the sentry.

He moved back into the panel and disappeared while the valet closed it. A moment later he, too, picked up his hat and hurried out.

At the Wilkeshire Club a large number of hunters had arrived for the imitation meet. Elaine, Aunt Josephine, Del Mar and myself rode up and were greeted by them as the Master of Fox Hounds assembled us. Off a bit, a splendid pack of hounds was held by the huntsman while they debated whether to hold a paper chase or to try a drag hunt.

"You start your cross-country riding early," commented Del Mar.

"Yes," answered Elaine. "You see we can hardly wait until autumn and the weather is so fine and cool, we feel that we ought to get into trim during the summer. So we have paper chases and drag hunts as soon as we can, mainly to please the younger set."

The chase was just about to start, when the valet came up. Del Mar caught his eye and excused himself to us. What he said, we could not hear, but Del Mar frowned, nodded and dismissed him.

Just then the horn sounded and we went off, dashing across the road into a field in full chase after the hounds, taking the fences and settling down to a good half hour's run over the most beautiful country I have ever seen.

The hounds had struck the trail, which of course, as was finally decided, was nothing but that laid by an anise-seed bag dragged over the ground. It was none the less, in fact perhaps more interesting for that.

The huntsman winded his horn and mirthful shouts of "Gone away!" sounded in imitation of a real hunt. The blast of the horn once heard is never forgotten, thrilling the blood and urging one on.

The M. F. H. seemed to be everywhere at once, restraining those who were too eager and saving the hounds often from being ridden down by those new to the hunt who pressed them.

Elaine was one of the foremost. Her hunter was one carefully trained, and she knew all the tricks of the game.

Somehow, I got separated, at first, from the rest and followed, until finally I caught up, and then kept behind one of the best riders.

Del Mar also got separated, but, as I afterward learned, by intention, for he deliberately rode out of the course at the first opportunity he had and let Elaine and the rest of us pass without seeing him.

Elaine's blood was up, but somehow, in spite of herself, she went astray, for the hounds had distanced the fleetest riders and she, in an attempt at a short cut over the country which she thought she knew so well, went a mile or so out of the way.

She pulled up in a ravine and looked about. Intently she listened. There was no sign of the hunt. She was hot and tired and thirsty and, at a loss just to join the field again, she took this chance to dismount and drink from a clear stream fed by mountain springs.

As she did so, floating over the peaceful woodland air came the faint strains of the huntsman's horn, far, far off. She looked about, straining her eyes and ears to catch the direction of sound. Just then her horse caught the winding of the horn. His ears went erect and without waiting he instantly galloped off, leaving her. Elaine called and ran after him, but it was too late. She stopped and looked dejectedly as he disappeared. Then she made her way up the side of the ravine, slowly.

On she climbed until, to her surprise, she came to the ruins of an old hotel. She remembered, as a child, when it had been famous as a health resort, but it was all changed now—a wreck. She looked at it a moment, then, as she had nothing better to do, approached it.

She advanced toward a window of the dining-room and looked in.

. . . . . . .

Del Mar waited only until the last straggler had passed. Then he dashed off as fast as his horse would carry him straight toward the deserted hotel which served him as headquarters for the supplies he was accumulating. As he rode up, one of his sentries appeared, as if from nowhere, and, seeing who it was, saluted.

"Here, take care of this horse," ordered Del Mar, dismounting and turning the animal over to the man, who led him to the rear of the building as Del Mar entered the front door, after giving a secret signal.

There were his men in goggles and masks at the work, which his knock had interrupted.

"Give me a mask before I enter the room," he ordered of the man who had answered his signal.

The man handed the mask and goggles to him, as well as a coat, which he put on quickly. Then he entered the room and looked at the rapid progress of the work.

"Where's the prisoner?" asked Del Mar a moment later, satisfied at the progress of his men.

"In the attic room," one of his lieutenants indicated.

"I'd like to take a look at him," added Del Mar, just about to turn and leave the room.

As he did so, he happened to glance at one of the windows. There, peering through the broken shutters, was a face—a girl's face— Elaine!

"Just what I wanted guarded against," he cried angrily, pointing at the window. "Now—get her!"

The men had sprung up at his alarm. They could all see her and with one accord dashed for the door. Elaine sprang back and they ran as they saw that she was warned. In genuine fear now she too ran from the window. But it was too late.

For just then the sentry who had taken Del Mar's horse came from behind the building cutting off her retreat. He seized her just as the other men ran out. Elaine stared. She could make nothing of them. Even Del Mar, in his goggles and breathing mask was unrecognizable.

"Take her inside," he ordered disguising his voice. Then to the sentry he added, "Get on guard again and don't let any one through."

Elaine was hustled into the big deserted hallway of the hotel, just as the tramp had been.

"You may go back to work," Del Mar signed to the other men, who went on, leaving one short but athletic looking fellow with Del Mar and Elaine.

"Lock her up, Shorty," ordered Del Mar, "and bring the other prisoner to me down here."

None too gently the man forced Elaine up-stairs ahead of him.

. . . . . . .

In the attic, the tramp, pacing up and down, heard footsteps approach on the stairs and enter the next room.

Quickly he ran to the doorway and peered through the keyhole. There he could see Elaine and the small man enter. He locked the door to the hall, then quickly took a step toward the door into the tramp's room.

There was just time enough for the tramp to see his approach. He ran swiftly and softly over to the further corner and dropped down as if sound asleep. The key turned in the lock and the small man entered, careful to lock the door to Elaine's room. He moved over to where the tramp was feigning sleep.

"Get up," he growled, kicking him.

The tramp sat up, yawning and rubbing his eyes. "Come now, be reasonable," demanded the man. "Follow me."

He started toward the door into the hall. He never reached it. Scarcely was his hand on the knob when the tramp seized him and dragged him to the floor. One hand on the man's throat and his knees on his chest, the tramp tore off the breathing mask and goggles. Already he had the man trussed up and gagged.

Quickly the tramp undressed the man and left him in his underclothes, still struggling to get loose, as he took Shorty's clothes, including the strange head-gear, and unlocked the door into the next room with the key he also took from him.

Elaine was pacing anxiously up and down the little room into which she had been thrown, greatly frightened.

Suddenly the door through which her captor had left opened hurriedly again. A most disreputable looking tramp entered and locked the door again. Elaine started back in fear.

He motioned to her to be quiet. "You'll never get out alive," he whispered, speaking rapidly and thickly, as though to disguise his voice. "Here—take these clothes. Do just as I say. Put them on. Put on the mask and goggles. Cover up your hair. It is your only chance."

He laid the clothes down and went out into the hallway. Outside he listened carefully at the head of the stairs and looked about expecting momentarily to be discovered.

Elaine understood only that suddenly a friend in need had appeared. She changed her clothes quickly, finding fortunately that they fitted her pretty well. By pulling the hat over her hair and the goggles over her eyes and tying on the breathing mask, she made a very presentable man.

Cautiously she pushed open the door into the hallway. There was the tramp. "What shall I do?" she asked.

"Don't talk," he whispered close to her ear. "Go out—and if you meet any one, just salute and walk past."

"Yes—yes, I understand," she nodded back, "and—thank you."

He gave her no time to say more, even if it had been safe, but turned and locked the door of her room.

Trying to keep the old stairway from creaking and betraying her, she went down. She managed to reach the lower hallway without seeing anybody or being discovered. Quietly she went to the door and out. She had not gone far when she met an armed man, the sentry, who had been concealed in the shrubbery.

"Who goes there?" he challenged.

Elaine did not betray herself by speaking, but merely saluted and passed on as fast as she could without exciting further suspicion. Nonplused, the man turned and watched her curiously as she moved away down the path.

"Where's HE going?" the sentry muttered, still staring.

Elaine in her eagerness was not looking as carefully where she was going as she was thinking about getting away in safety. Suddenly an overhanging branch of a tree caught her hat and before she knew it pulled it off her head. There was no concealing her golden hair now.

"Stop!" shouted the sentry.

Elaine did not pause, but dived into the bushes on the side of the path, just as the man fired and ran forward, still shouting for her to halt. She ran as fast as she could, pulling off the goggles and mask and looking back now and then in terror at her pursuer who was rapidly gaining on her.

Before she could catch herself she missed her footing and slipped over the edge of a gorge. Down she went, with a rush. It was unfortunate, dangerous, but, after all, it was the only thing that saved her, at least for the time. Half falling, half sliding, scratching herself and tearing her clothes, she descended.

The sentry checked himself just in time at the top of the gorge and leaned as far over the edge as he dared. He raised his gun again and fired. But Elaine's course was so hidden by the trees and so zigzag that he missed again. A moment he hesitated, then started and climbed down after her as fast as he could.

At the bottom of the hill she picked herself up and dashed again into the woods, the sentry still after her and gaining again.

At the same time, we who were still in the chase had circled about the country until we were very near where we started. Following the dogs over a rail fence, I drew up suddenly, hearing a scream.

There was Elaine, on foot, running as if her life depended on it. I needed no second glance. Behind her was a man with a rifle, almost overtaking her.

As luck would have it, the momentum of my horse carried me right at them. Careful to avoid Elaine, I rode square at the man, striking at him viciously with my riding crop before he knew what had struck him.

The fellow dropped, stunned. I leaped from my horse and ran to her, just as the rest of the hunt came up.

Eagerly questioning us, they gathered about.

Having waited until he was sure that Elaine had got away safely, the old tramp slowly and carefully followed down the stairs of the ruined hotel.

As he went down, he heard a shot from the woods. Could it be one of the sentries? He looked about keenly, hesitating just what to do.

In an instant, down below, he heard the scurry of footsteps from the improvised laboratory and shouts. He turned and stealthily ran up-stairs, just as the door opened.

The tramp had not been the only one who had been alarmed by the shot of the sentry.

Del Mar was talking again to the men when it rang out. "What's that?" he exclaimed. "Another intruder?"

The men stared at him blankly, while Del Mar dashed for the door, followed by them all. In the hall he issued his orders quickly.

"Here, you fellows," he called dividing the men, "get outside and see what is doing. You other men follow me. I want you to see if everything's all right up above."

Meanwhile the tramp had gained the upper hallway and dashed past the room which he occupied. Outside, in the hall, Del Mar and his men rushed up to the door of the room in which Elaine had been thrown. It was locked and they broke in. She was gone!

On into the next room they dashed, bearing down this door also. There was Shorty, trussed up in his underclothes. They hastened to release him.

"Where are they—where's the tramp?" demanded Del Mar angrily.

"I think I heard some one on the roof," replied Shorty weakly. He was right. The tramp had managed to get through a scuttle on the roof. Then he climbed down to the edge and began to let himself hand over hand down the lightning rod.

Reaching the ground safely, he scurried about to the back of the building. There, tied, was the horse which Del Mar had ridden to the hunt. He untied it, mounted and dashed off down the path through the woods, taking the shortest cut in the direction of Fort Dale.

Dusty and flecked with foam, the tramp and his mount, a strange combination, were instantly challenged by the sentry at the Fort.

"I must see Lieutenant Woodward immediately," urged the tramp.

A heated argument followed until finally a corporal of the guards was called and led off the tramp toward the headquarters.

It was only a few minutes before Woodward was convinced of the identity of the tramp with his friend, Professor Arnold. At the head of a squad of cavalry, Woodward and the tramp dashed off.

Already on the qui vive, Elaine heard the sound of hoof-beats long before the rest of us crowded around her. For the moment we all stood ready to repel an attack from any quarter.

But it was not meant for us. It was Woodward at the head of a score or so of cavalrymen. With him rode a tramp on a horse which was strangely familiar to me.

"Oh," cried Elaine, "there's the man who saved me!"

As they passed, the tramp paused a moment and looked at us sharply. Although he carefully avoided Elaine's eyes, I fancied that only when he saw that she was safe was he satisfied to gallop off and rejoin the cavalry.

. . . . . . .

Around the old hotel, in every direction, Del Mar's men were searching for the tramp and Elaine, while in the hotel another search was in progress.

"Have you discovered anything?" asked Del Mar, entering.

"No, sir," they reported.

"Confound it!" swore Del Mar, going up-stairs again.

Here also were men searching. "Find anything?" he asked briefly.

"No luck," returned one.

Del Mar went on up to the top floor and out through the open scuttle to the roof. "That's how he got away, all right," he muttered to himself, then looking up he exclaimed under his breath, as his eye caught something far off, "The deuce—what's that?"

Leaning down to the scuttle, he called, "Jenkins—my field- glasses—quick!"

One of his men handed them to him and he adjusted them, gazing off intently. There he could see what looked like a squad of cavalry galloping along headed by an officer and a rough looking individual.

"Come—we must get ready for an attack!" he shouted diving down the scuttle again.

In the laboratory dining-room, his men, recalled, hastily took his orders. Each of them seized one of the huge black rubber newly completed gas bombs and ran out, making for a grove near-by.

Quickly as Del Mar had acted, it was not done so fast but that the troop of cavalry as they pulled up on the top of a hill and followed the directing finger of the tramp could see men running to the cover of the grove.

"Forward!" shouted Woodward.

As if all were one machine, the men and horses shot ahead, until they came to the grove about the old hotel. There they dismounted and spread out in a semi-circular order, advancing on the grove. As they did so, shots rang out from behind the trees. Del Mar's men, from the shelter were firing at them. But it seemed hopeless for the fugitives.

"Ready!" ordered Del Mar as the cavalrymen advanced, relentless.

Each of his men picked up one of the big black gas bombs and held it high up over his head.

"Come on!" urged Woodward.

His men broke into a charge on the grove.

"Throw them!" ordered Del Mar.

As far as he could hurl it, each of the men sent one of the black globes hurtling through the air. They fell almost simultaneously, a long line of them, each breaking into a thousand bits. Instantly dense, greenish-yellow fumes seemed to pour forth, enveloping everything. The wind which Del Mar had carefully noted when he chose the position in the grove, was blowing from his men toward the only position from which an attack could be made successfully.

Against Woodward's men as they charged, it seemed as if a tremendous, slow-moving wall of vapor were advancing from the trees. It was only a moment before it completely wrapped them in its stifling, choking, suffocating embrace. Some fell, overcome. Others tried to run, clutching frantically at their throats and rubbing their eyes.

"Get back—quick—till it rolls over," choked Woodward.

Those who were able to do so, picked up their stupefied comrades and retreated, as best they could, stumbling blindly back from the fearful death cloud of chlorine.

Meantime, under cover of this weird defence, Del Mar and his men, their own faces covered and unrecognizable in their breathing masks and goggles, dashed to one side, with a shout and disappeared walking and running behind and even through the safety of their impregnable gas barrier.

More slowly we of the hunt had followed Woodward's cavalry until, some distance off, we stood, witnessing and wondering at the attack. To our utter amazement we saw them carrying off their wounded and stupefied men. We hurried forward and gathered about, offering whatever assistance we could to resuscitate them.

As Elaine and I helped, we saw the unkempt figure of the tramp borne in and laid down. He was not completely overcome, having had presence of mind to tie a handkerchief over his nose and mouth.

Elaine hurried toward him with an exclamation of sympathy. Just recovering full consciousness, he heard her.

With the greatest difficulty, he seemed to summon some reserve force not yet used. He struggled to his feet and staggered off, as though he would escape us.