Harry Fleming had, of course, given up all hope of catching Graves by a direct pursuit by the time he accepted the offer of a ride in the motor truck that was carrying vegetables for the troops in quarters in London. His only hope now was to get his information to Colonel Throckmorton as soon as possible. At the first considerable town they reached, where he found a telegraph office open, he wired to the colonel, using the code which he had memorized. The price of a couple of glasses of beer had induced the driver and the soldier to consent to a slight delay of the truck, and he tried also to ring up Jack Young's house and find out what had happened to Dick.

When he found that the line was out of order he leaped at once to the same conclusion that Jack and Dick had reached—that it had been cut on purpose. He could not stay to see if it would be reopened soon. A stroke of luck came his way, however. In this place Boy Scouts were guarding the gas works and an electric light and power plant, and he found one squad just coming off duty. He explained something of his errand to the patrol leader, and got the assurance that the telephone people should be made to repair the break in the wire.

"We'll see to it that they find out what is the trouble, Fleming," said the patrol leader, whose name was Burridge. "By the way, I know a scout in your troop—Graves. He was on a scout with us a few weeks ago, when he was visiting down here. Seemed to be no end of a good fellow."

Harry was surprised for he had heard nothing of this before. But then that was not strange. He and Graves were not on terms of intimacy, by any means. He decided quickly not to say anything against Graves. It could do no good and it might do harm.

"Right," he said. "I know him—yes. I'll be going, then. You'll give my message to Mercer or Young if there's any way of getting the line clear?"

"Yes, if I sit up until my next turn of duty," said Burridge, with a smile. "Good luck, Fleming."

Then Harry was off again. Dawn was very near now. The east, behind him, was already lighted up with streaks of glowing crimson. Dark clouds were massed there, and there was a feeling in the air that carried a foreboding of rain, strengthening the threat of the red sky. Harry was not sorry for that. There would be work at Bray Park that might well fare better were it done under leaden skies.

As he rode he puzzled long and hard over what he had learned. It seemed to him that these German spies were taking desperate chances for what promised to be, at best, a small reward. What information concerning the British plans could they get that would be worth all they were risking? The wireless at Bray Park; the central station near Willesden, whence the reports were heliographed—it was an amazingly complete chain. And Harry knew enough of modern warfare to feel that the information could be important only to an enemy within striking distance.

That was the point. It might be interesting to the German staff to know the locations of British troops in England, and, more especially, their destinations if they were going abroad as part of an expeditionary force to France or Belgium. But the information would not be vital; it didn't seem to Harry that it was worth all the risk implied. But if, on the other hand, there was some plan for a German invasion of England, then he would have no difficulty in understanding it. Then knowledge of where to strike, of what points were guarded and what were not, would be invaluable.

"But what a juggins I am!" he said. "They can't invade England, even if they could spare the troops. Not while the British fleet controls the sea. They'd have to fly over."

And in that half laughing expression he got the clue he was looking for. Fly over! Why not? Flight was no longer a theory, a possibility of the future. It was something definite, that had arrived. Even as he thought of the possibility he looked up and saw, not more than a mile away, two monoplanes of a well-known English army type flying low.

"I never thought of that!" he said to himself.

And now that the idea had come to him, he began to work out all sorts of possibilities. He thought of a hundred different things that might happen. He could see, all at once, the usefulness Bray Park might have. Why, the place was like a volcano! It might erupt at any minute, spreading ruin and destruction in all directions. It was a hostile fortress, set down in the midst of a country that, even though it was at war, could not believe that war might come home to it.

He visualized, as the truck kept on its plodding way, the manner in which warfare might be directed from a center like Bray Park. Thence aeroplanes, skillfully fashioned to represent the British 'planes, and so escape quick detection, might set forth. They could carry a man or two, elude guards who thought the air lanes safe, and drop bombs here, there—everywhere and anywhere. Perhaps some such aerial raid was responsible for the explosion that had freed him only a very few hours before.

Warfare in England, carried on thus by a few men, would be none the less deadly because it would not involve fighting. There would be no pitched battles, that much he knew. Instead, there would be swift, stabbing raids. Water works, gas works, would be blown up. Attempts would be made to drop bombs in barracks, perhaps. Certainly every effort would be made to destroy the great warehouses in which food was stored. It was new, this sort of warfare; it defied the imagination. And yet it was the warfare that, once he thought of it, it seemed certain that the Germans would wage.

He gritted his teeth at the thought of it. Perhaps all was fair in love and war, as the old proverb said. But this seemed like sneaky, unfair fighting to him. There was nothing about it of the glory of warfare. He was learning for himself that modern warfare is an ugly thing. He was to learn, later, that it still held its possibilities of glory, and of heroism. Indeed, for that matter, he was willing to grant the heroism of the men who dared these things that seemed to him so horrible. They took their lives in their hands, knowing that if they were caught they would be hung as spies.

The truck was well into London now, and the dawn was full. A faint drizzle was beginning to fall and the streets were covered with a fine film of mud. People were about, and London was arousing itself to meet the new day. Harry knew that he was near his journey's end. Tired as he was, he was determined to make his report before he thought of sleep. And then, suddenly, around a bend, came a sight that brought Harry to his feet, scarcely able to believe his eyes. It was Graves, on a bicycle. At the sight of Harry on the truck he stopped. Then he turned.

"Here he is!" he cried. "That's the one!"

A squad of men on cycles, headed by a young officer, came after Graves.

"Stop!" called the officer to the driver.

Harry stared down, wondering.

"You there—you Boy Scout—come down!" said the officer.

Harry obeyed, wondering still more. He saw the gleam of malignant triumph on the face of Graves. But not even the presence of the officer restrained him.

"Where are those papers you stole from me, you sneak?" he cried.

"You keep away from me!" said Graves. "You—Yankee!"

"Here, no quarreling!" said the officer. "Take him, men!"

Two of the soldiers closed in on Harry. He stared at them and then at the officer, stupefied.

"What—what's this?" he stammered.

"You're under arrest, my lad, on a charge of espionage!" said the officer. "Espionage, and conspiracy to give aid and comfort to the public enemy. Anything you say may be used against you."

For a moment such a rush of words came to Harry that he was silent by the sheer inability to decide which to utter first. But then he got control of himself.

"Who makes this charge against me!" he asked, thickly, his face flushing scarlet in anger.

"You will find that out in due time, my lad. Forward—march!"

"But I've got important information! I must be allowed to see Colonel Throckmorton at once! Oh, you've no idea of how important it may be!"

"My orders are to place you under arrest. You can make application to see anyone later. But now I have no discretion. Come! If you really want to see Colonel Throckmorton, you had better move on."

Harry knew as well as anyone the uselessness of appealing from such an order, but he was frantic. Realizing the importance of the news he carried, and beginning to glimpse vaguely the meaning of Graves and his activity, he was almost beside himself.

"Make Graves there give back the papers he took from me!" he cried.

"I did take some papers, lieutenant," said Graves, with engaging frankness. "But they were required to prove what I had suspected almost from the first—that he was a spy. He was leading an English scout from his own patrol into trouble, too. I suppose he thought he was more likely to escape suspicion if he was with an Englishman."

"It's not my affair," said the lieutenant, shrugging his shoulders. He turned to Harry. "Come, my lad. I hope you can clear yourself. But I've only one thing to do—and that is to obey my orders."

Harry gave up, then, for the moment. He turned and began walking along, a soldier on each side. But as he did so Graves turned to the lieutenant.

"I'll go and get my breakfast, then, sir," he said. "I'll come on to Ealing later. Though, of course, they know all I can tell them already."

"All right," said the officer, indifferently.

"You're never going to let him go!" exclaimed Harry, aghast. "Don't you know he'll never come back?"

"All the better for you, if he doesn't," said the officer. "That's enough of your lip, my lad. Keep a quiet tongue in your head. Remember you're a prisoner, and don't try giving orders to me."