“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’ll 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 got no idea 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 along, 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.”

CHAPTER XIV

THE TRAP

The bullet that sang over their heads effectually broke up the threatened trouble between Dick Mercer and Jack Young on one side, and the telephone linemen on the other.  With one accord they obeyed that guttural order, “Hands oop!”