On the tram car he was fairly safe. It happened, fortunately, that he had plenty of money with him. And his first move, when he felt it was safe, was to get off the tram and look for a cab. He found a taxicab in a short time, one of those that had escaped requisition by the government, and in this he drove to an outfitting shop, were he bought new clothes. He reasoned that he would be looked for all over, and that if, instead of appearing as a Boy Scout in character dress of the organization, he was in ordinary clothes, he would have a better chance. He managed the change easily, and then felt that it was safe for him to try and get into communication with Dick.

In this attempt luck was with him again. He called for the number of the vicarage at Bray, only to find that the call was interrupted again at the nearest telephone center. But this time he was asked to wait, and in a minute he heard Jack Young's voice in his ear.

"We came over to explain about the wire's being cut," said Jack. "Dick's all right. He's here with me. Where are you? We've got to see you just as soon as we can."

"In London, but I'm coming down. I'm going to try to get a motor car, too. I'm in a lot of trouble, Jack - it's Graves."

"Come on down. We'll walk out along the road towards London and meet you. We've got a lot to tell you, but I'm afraid to talk about it over the telephone."

"All right! I'll keep my eyes open for you."

Getting a motor car was not easy. A great many had been taken by the government. But Harry remembered that one was owned by a business friend of his father's, an American, and this, with some difficulty, he managed to borrow. He was known as a careful driver. He had learned to drive his father's car at home, and Mr. Armstrong knew it. And so, when Harry explained that it was a matter of the greatest urgency, he got it - since he had established a reputation for honor that made Mr. Armstrong understand that when Harry said a thing was urgent, urgent it must be.

Getting out of London was easy. If a search was being made for him - and he had no doubt that that was true - he found no evidence of it. His change of clothes was probably what saved him, for it altered his appearance greatly. So he came near to Bray, and finally met his two friends.



Chapter XVI

The Cipher

"What happened to you?" asked Jack and Dick in chorus.

Swiftly Harry explained. He told of his arrest as a spy and of his escape. And when he mentioned the part that Ernest Graves had played in the affair, Jack and Dick looked at one another.

"We were afraid of something like that, said Jack. "Harry, we've found out a lot of things, and we don't know what they mean! We're sure something dreadful is going to happen tonight. And we're sure, too, that Bray Park is going to be the centre of the trouble."

"Tell me what you know," said Harry, crisply. "Then we'll put two and two together. I say, Jack, we don't want to be seen, you know. Isn't there some side road that doesn't lead anywhere, where I can run in with the car while we talk?"

"Yes. There's a place about a quarter of a mile further on that will do splendidly," he replied.

"All right. Lead the way! Tell me when we come to it. I've just thought of something else I ought to never have forgotten. At least, I thought of it when I took the things out of my pockets while I was changing my clothes."

They soon came to the turning Jack had thought of, and a run of a few hundred yards took them entirely out of sight of the main road, and to a place where they were able to feel fairly sure of not being molested.

Then they exchanged stories. Harry told his first. Then he heard of Dick's escape, and of his meeting with Jack. He nodded at the story they had heard from Graffer Hodge.

"That accounts for how Graves knew," he said, with much satisfaction. "What happened then?"

When he heard of how they had thought too late of calling Colonel Throckmorton by telephone he sighed.

"If you'd only got that message through before Graves did his work!" he said. "He'd have had to believe you then, of course. How unlucky!"

"I know," said Jack. "We were frightfully sorry. And then we went out to find where the wire was cut, and then got Dick. But I got away, and I managed to stay fairly close to them. I followed them when they left Dick in a little stone house, as a prisoner, and I heard this - I heard them talking about getting a big supply of petrol. Now what on earth do they want petrol for? They said there would still be plenty left for the automobiles - and then that they wouldn't need the cars any more, anyhow! What on earth do you make of that, Harry?"

"Tell me the rest, then I'll tell you what I think," said Harry. "How did you get Dick out? And did you hear them saying anything that sounded as if it might be useful, Dick?"

"That was fine work!" he said, when he had heard a description of Dick's rescue. "Jack, you seem to be around every time one of us gets into trouble and needs help!"

Then Dick told of the things he had overheard - the mysterious references to Von Wedel and to things that were to be done to the barracks at Ealing and Houndsditch. Harry got out a pencil and paper then, and made a careful note of every name that Dick mentioned. Then he took a paper from his pocket.

"Remember this, Dick?" he asked. "It's the thing I spoke of that I forgot until I came across it in my pocket this morning."

"What is it, Harry?"

"Don't you remember what we watched them heliographing some messages, and put down the Morse signs? Here they are. Now the thing to do is to see if we can't work out the meaning of the code. If it's a code that uses words for phrases we've probably stuck, but I think its more likely to depend on inversions."

"What do you mean, Harry?" asked Jack. "I'm sorry I don't know anything about codes and ciphers."

"Why, there are two main sorts of codes, Jack, and, of course, thousands of variations of each of those principal kinds. In one kind the idea is to save words - in telegraphing or cabling. So the things that are likely to be said are represented by one word. For instance Coal, in a mining code, might mean 'struck vein at two hundred feet level.' In the other sort of code, the letters are changed. That is done in all sorts of ways, and there are various tricks. The way to get at nearly all of them is to find out which letter or number or symbol is used most often, and to remember that in an ordinary letter E will appear almost twice as often as any other letter - in English, that is."

"But won't this be in German?"

"Yes. That's just why I wanted those names Dick heard. They are likely to appear in any message that was sent. So, if we can find words that correspond in length to those, we may be able to work it out. Here goes, anyhow!"

For a long time Harry puzzled over the message. He transcribed the Morse symbols first into English letters and found they made a hopeless and confused jumble, as he had expected. The key to the letter E was useless, as he had also expected. But finally, by making himself think in German, he began to see a light ahead. And after an hour's hard work he gave a cry of exultation.

"I believe I've got it!" he cried. "Listen and see if this doesn't sound reasonable!"

"Go ahead!" said Jack and Dick, eagerly.

"Here it is," said Harry. "Petrol just arranged. Supply on way. Reach Bray Friday. Von Wedel may come. Red light markers arranged. Ealing Houndsditch Buckingham Admiralty War Office. Closing."

They stared at him, mystified.

"I suppose it does make sense," said Dick. "But what on earth does it mean, Harry?

"Oh, can't you see?" cried Harry. "Von Wedel is a commander of some sort - that's plain, isn't it? And he's to carry out a raid, destroying or attacking the places that are mentioned! How can he do that? He can't be a naval commander. He can't be going to lead troops, because we know they can't land. Then how can he get here? And why should he need petrol?"

They stared at him blankly. Then, suddenly, Dick understood.

"He'll come through the air!" he cried.

"Yes, in one of their big Zeppelins!" said Harry. "I suppose she has been cruising off the coast. She's served as a wireless relay station, too. The plant here at Bray Park could reach her, and she could relay the message on across the North Sea, to Helgoland or Wilhelmshaven. She's waited until everything was ready."

"That what they mean by the red light markers, then?"

"Yes. They could be on the roofs of houses, and masked, so that they wouldn't be seen except from overhead. They'd be in certain fixed positions, and the men on the Zeppelins would be able to calculate their aim, and drop their bombs so many degrees to the left or right of the red marking lights."

"But we've got aeroplanes flying about, haven't we?" said Jack. "Wouldn't they see those lights and wonder about them?"

"Yes, if they were showing all the time. But you can depend on it that these Germans have provided for all that. They will have arranged for the Zeppelin to be above the position, as near as they can guess them, at certain times - and the lights will only be shown at those times, and then only for a few seconds. Even if someone else sees them, you see, there won't be time to do anything."

"You must be right, Harry!" said Jack, nervously. "There's no other way to explain that message. How are we going to stop them?"

"I don't know yet, but we'll have to work out some way of doing it. It would be terrible for us to know what had been planned and still not be able to stop them! I wish I knew were Graves was. I'd like to..."

He stopped, thinking hard.

"What good would that do?"

"Oh, I don't want him - not just now. But I don't want him to see me just at present. I want to know where he is so that I can avoid him."

"Suppose I scout into Bray?" suggested Jack. "I can find out something that might be useful, perhaps. If any of them from Bray Park have come into the village today I'll hear about it."

"That's a good idea. Suppose you do that, Jack. I don't know just what I'll do yet. But if I go away from here before you come back, Dick will stay. I've got to think - there must be some way to beat them!"



Chapter XVII

A Capture From The Skies

Jack went off to see what he could discover, and Harry, left behind with Dick, racked his brains for some means of blocking the plan he was so sure the Germans had made. He was furious at Graves, who had discredited him with Colonel Throckmorton, as he believed. He minded the personal unpleasantness involved far less than the thought that his usefulness was blocked, for he felt that not information he might bring would be received now.

As he looked around it seemed incredible that such things as he was trying to prevent could even be imagined. After the early rain, the day had cleared up warm and lovely, and it was now the most perfect of things, a beautiful summer day in England. The little road they had taken was a sort of blind alley. It had brought them to a meadow, whence the hay had already been cut. At the far side of this ran a little brook, and all about them were trees. Except for the call of birds, and the ceaseless hum of insects, there was no sound to break the stillness. It was a scene of peaceful beauty that could not be surpassed anywhere in the world. And yet, only a few miles away, at the most, were men who were planning deliberately to bring death and destruction upon helpless enemies - to rain down death from the skies.

By very contrast to the idyllic peace of all about them, the terrors of war seemed more dreadful. That men who went to war should be killed and wounded, bat though it was, still seemed legitimate. But his driving home of an attack upon a city all unprepared, upon the many non-combatants who would be bound to suffer, was another and more dreadful thing. Harry could understand that it was war, that it was permissible to do what these Germans were planned. And yet —

His thoughts were interrupted by a sudden change in the quality of the noisy silence that the insects made. Just before he noticed it, half a dozen bees had been humming near him. Now he heard something that sounded like the humming of a far vaster bee. Suddenly it stopped, and, as it did, he looked up, his eyes as well as Dick's being drawn upward at the same moment. And they saw, high above them, an aeroplane with dun colored wings. Its engine had stopped and it was descending now in a beautiful series of volplaning curves.

"Out of essense - he's got to come down," said Harry, appraisingly, to Dick. "He'll manage it all right, too. He knows his business through and through, that chap."

"I wonder where he'll land," speculated Dick.

"He's got to pick an open space, of course," said Harry. "And there aren't so many of them around here. By Jove!"

"Look! He's certainly coming down fast!" exclaimed Dick.

"Yes - and, I say, I think he's heading for this meadow! Come on — start that motor, Dick!"

"Why? Don't you want him to see us?"

"I don't mind him seeing us - I don't want him to see the car," explained Harry. "We'll run it around that bend, out of sight from the meadow."

"Why shouldn't he see it?"

"Because if he's out of petrol, he'll want to take all we've got and we may not want him to have it. We don't know who he is, yet."

The car was moving as Harry explained. As soon as the meadow was out of sight, Harry stopped the engine and got out of the car.

"He may have seen it as he was coming down - the car, I mean," he said. "But I doubt it. He's got other things to watch. That meadow for one - and all his levers and his wheel. Guiding an aeroplane in a coast like that down the air is no easy job."

"Have you ever been up, Harry?"

"Yes, often. I've never driven one myself, but I believe I could if I had to. I've watched other people handle them so often that I know just about everything that has to be done.

"That's an English monoplane. I've seen them ever so often," said Dick. "It's an army machine, I mean. See it's number? It's just coming in sight of us now. Wouldn't you like to fly her though?"

"I'd like to know what it's doing around here," said Harry. "And it seems funny to me if an English army aviator has started out without enough petrol in his tank to see him through any flight he might be making. And wouldn't he have headed for one of his supply stations as soon as he found out he was running short, instead of coming down in country like this?"

Dick stared at him.

"Do you think it's another spy?" he asked.

"I don't think anything about it yet, Dick. But I'm not going to be caught napping. That's a Bleriot - and the British army flying corps uses Bleriots. But anyone with the money can buy one and make it look like an English army plane. Remember that."

There was no mistaking about the monoplane when it was once down. Its pilot was German; he was unmistakably so. He had been flying very high and when he landed he was still stiff from the cold.

"Petrol!" he cried eagerly, as he saw the two boys. "Where can I get petrol? Quick! Answer me!"

Harry shot a quick glance at Dick.

"Come on," he said, beneath his breath. "We've got to get him and tie him up."

The aviator, cramped and stiffened as he was by the intense cold that prevails in the high levels where he had been flying, was no match for them. As they sprang at him his face took on the most ludicrous appearance of utter surprise. Had he suspected that they would attack him he might have drawn a pistol. As it was, he was helpless before the two boys, both in the pink of condition and determined to capture him. He made a struggle, but in two minutes he was laying roped, tied, and utterly helpless. He was not silent; he breathed the most fearful threats as to what would happen to them. But neither boy paid any attention to him.

"We've got to get him to the car," said Harry. "Can we drag him?"

"Yes. But if we loosen his feet a little, he could walk," suggested Dick. "That would be ever so much easier for him, and for us too. I should hate to be dragged. Let's make him walk."

"Right - and a good idea!" said Harry. He loosened the ropes about the aviator's feet, and helped him to stand.

"March!" he said. "Don't try to get away - I've got a leading rope, you see."

He did have a loose end of rope, left over from a knot, and with this he proceeded to lead the enraged German to the automobile. It looked for all the world as if he were leading a dog, and for a moment Dick doubled up in helpless laughter. The whole episode had it's comic side, but it was serious, too.

"Now we've got to draw off the gasoline in the tank in this bucket," said Harry. The German had been bestowed in the tonneau, and made as comfortable as possible with rugs and cushions. His feet were securely tied again, and there was no chance for him to escape.

"What are you going to do?" asked Dick. "Are you going to try to fly in that machine?"

"I don't know, yet. But I'm going to have it ready, so that I can if I need to," said Harry. "That Bleriot maybe the saving of us yet, Dick. There's no telling what we shall have to do."

Even as he spoke, Harry was making new plans, rendered possible by this gift from the skies. He was beginning, at last, to see a way to circumvent the Germans. What he had in mind was risky, certainly, and might prove perilous in the extreme. But he did not let that aspect of the situation worry him. His one concern was to foil the terrible plan that the Germans had made, and he was willing to run any risk that would help him to do so.

"The Zeppelin is coming here to Bray Park - it's going to land here," said Harry. "And if it ever gets away from here there will be no way of stopping it from doing all the damage they have planned, or most of it. Thanks to Graves, we wouldn't be believed if we tell what we know - we'd probably just be put in the guard house. So we've got to try to stop it ourselves."

They had reached the Bleriot by that time. Harry filled the tank, and looked at the motor. Then he sat in the driver's seat and practiced with the levers, until he decided that he understood them thoroughly. And, as he did this, he made his decision.

"I'm going into Bray Park tonight," he said. "This is the only way to get in."

"And I'm going with you," announced Dick.



Chapter XVIII

Vindication

At first Harry refused absolutely to consent to Dick's accompanying him, but after a long argument he was forced to yield.

"Why should you take all the risks when it isn't your own country, especially?" asked Dick, almost sobbing. "I've got a right to go! And, besides, you may need me."

That was true enough, as Harry realized. Moreover, he had been investigating the Bleriot, and he discovered that it was one of the new safety type, with a gyroscope device to insure stability. That day was almost without wind, and therefore it seemed that if such an excursion could ever be safe, this was the time. He consented in the end, and later he was to be thankful that he had.

Once the decision was taken, they waited impatiently for the return of Jack Young. Harry foresaw protests from Jack when he found out what they meant to do, but for him there as an easy answer - there was room in the aeroplane for only two people, and there was no way of carrying an extra passenger.

It was early dusk when Jack returned, and he had the forethought to bring a basket of food with him - cold chicken, bread and butter, and milk, as well as some fruit.

"I didn't find out very much," he said, "except this. Someone from London has been asking about you both. And this much more - at least a dozen people have come down to Bray Park today from London."

"Did you see any sign of soldiers from London?"

"No," said Jack.

He was disappointed when he found out what they meant to do, but he took his disappointment pluckily when he saw that there was no help for it. Harry explained very quietly to both Jack and Dick what he meant to do and they listened, open mouthed, with wonder.

"You'll have your part to play, Jack," said Harry. "Somehow I can't believe that the letter I wrote to Colonel Throckmorton last night won't have some effect. You have got to scout around in case anyone comes and tell them all I've told you. You understand thoroughly, do you?"

"Yes," said Jack, quietly. "When are you going to start?"

"There's no use going up much before eleven o'clock," said Harry. "Before that we'd be seen, and, besides, if a Zepplin is coming, it wouldn't be until after that. My plan is to scout to the east and try to pick her up and watch her descend. I think I know just about where she'll land - the only place where there's room enough for her. And then -"

He stopped, and the others nodded, grimly.

"I imagine she'll have about a hundred and twenty miles to travel in a straight line - perhaps a little less," said Harry. "She can make that in about two hours, or less. Big as they are, those airships are painted so that they're almost invisible from below. So if she comes by night, getting here won't be as hard a job as it seems at first thought."

Then the three of them went over in every detail the plan Harry had formed. Dick and Jack took their places in the monoplane and rehearsed every movement they would have to make.

"I can't think of anything else that we can provide for now," said Harry, at last. "Of course, we can't tell what will come up, and it would be wonderful if everything came out just as we have planned. But we've provided for everything we can think of. You know where you are to be, Jack?"

"Yes."

"Then you'd better start pretty soon. Good-bye, Jack!" He held out his hand. "We could never have worked this out without you. If we succeed you'll have a big part in what we've done."

A little later Jack said good-bye in earnest, and then there was nothing to do but wait. About them the voices of the insects and frogs changed, with the darkening night. The stars came out, but the night was a dark one. Harry looked at his watch from time to time and at last he got up.

"Time to start!" he said.

He felt a thrill of nervousness as the monoplane rose into the air. After all, there was a difference between being the pilot and sitting still in the car. But he managed very well, after a few anxious moments in the ascent. And once they were clear of the trees and climbing swiftly, in great spirals, there was a glorious sensation of freedom. Dick caught his breath at first, then he got used to the queer motion, and cried aloud in his delight.

Harry headed straight into the east when he felt that he was high enough. And suddenly he gave a cry.

"Look!" he shouted in Dick's ear. "We didn't start a moment too soon. See her - that great big cigar-shaped thing, dropping over there?"

It was the Zepplin - the battleship of the air. She was dipping down, descending gracefully, over Bray Park.

"I was right!" cried Harry. "Now we can go to work at once - we won't have to land and wait!"

He rose still higher, then flew straight for Bray Park. They were high, but, far below, with lights moving about her, they could see the huge bulk of the airship, as long as a moderate sized ocean liner. She presented a perfect target.

"Now!" said Harry.

And at once Dick began dropping projectiles they had found in the aeroplane - sharply pointed shells of steel. Harry had examined these — he found they were really solid steel shot, cast like modern rifle bullets, and calculated to penetrate, even without explosive action, when dropped from a height.

From the first two that Dick dropped there was no result. But with the falling of the third a hissing sound came from below, and as Dick rapidly dropped three more, the noise increased. And they could see the lights flying - plainly the men were running from the monster. Its bulk lessened as the gas escaped from the great bag and then, in a moment more, there was a terrific explosion that rocked the monoplane violently. Had Harry not been ready for it, they might have been brought down.

But he had been prepared, and was flying away.

Down below there was now a great glare from the burning wreckage, lighting up the whole scene. And suddenly there was a sharp breaking out of rifle fire. At first he thought the men below had seen them, and were firing upward. But in a moment he saw the truth. Bray Park had been attacked from outside!

Even before they reached the ground, in the meadow where Harry and Jack had emerged from the tunnel, and Harry and Dick saw, to their wonder and delight, that the ground swarmed with khaki-clad soldiers. In the same moment Jack ran up to them.

"The soldiers have the place surrounded!" he cried, exultingly. "They must have believed your letter after all, Harry! Come on - there's a boat here! Aren't you coming over?"

They were rowing for the other shore before the words were well spoken. And, once over, they were seized at once by two soldiers.

"More of them," said one of the soldiers. "Where's the colonel?"

Without trying to explain, they let themselves be taken to where Colonel Throckmorton stood near the burning wreckage. At the sight of Harry his face lighted up.

"What do you know about this?" he asked, sternly, pointing to the wrecked airship.

Harry explained in a few words.

"Very good," said the colonel. "You are under arrest - you broke arrest this morning. I suppose you know that is a serious offense, whether your original arrest was justified or not?"

"I felt I had to do it, sir," said Harry. He had caught the glint of a smile in the colonel's eyes.

"Explain yourself, sir," said the colonel. "Report fully as to your movements today. Perhaps I shall recommend you for a metal instead of court marshalling you, after all."

And so the story came out, and Harry learned that the colonel had never believed Graves, but had chosen to let him think he did.

"The boy Graves is a German, and older than he seems," said the colonel. "He was here as a spy. He is in custody now, and you have broken up a dangerous raid and a still more dangerous system of espionage. If you hadn't come along with your aeroplane, we would never have stopped the raid. I had ordered aviators to be here, but it is plain that something has gone wrong. You have done more than well. I shall see to it that your services are properly recognized. And now be off with you, and get some sleep. You may report to me the day after tomorrow!"

THE END