"By Jove! Is that so?" ejaculated Canterbury, when Derek had reported the details required to back up his request for an armed party. "Right-o! I'll turn out a crowd in half a shake. Wait till I've informed the 'Adjy.', and then we'll see what's to be done." Lieutenant Canterbury was as good as his word. Having explained matters to the Adjutant, he led a file of airmen to the hangars, where the secret battleplanes were jealously hidden from prying eyes by an elaborate camouflage scheme. At the first of the sheds, in which the giant machines assembled for the purpose of bombing Berlin were stored, the Orderly Officer halted his men. "Carry on, Daventry," he said. "See if your merchant is knocking around. We'll stand by in case of an accident." Derek's investigation of the first shed drew blank. As he was entering the second he came face to face with the flying-officer he had befriended. "Hallo, George!" exclaimed the pilot of the disabled machine. "You're just the fellow I wanted to see. Hung around the mess for a deuce of a time, but it was _na poo._" "Better late than never," rejoined Derek. "We'll stroll back. S'pose you can spare the time?" The officer hesitated. Then: "Right-o! I'm on!" he exclaimed. "Can't stop very long, though. I'm on a special stunt with these bombers. By the way, do you happen to know----" Derek laid his hand heavily upon the pilot's shoulder. "Count von Peilfell," he said sternly, "I arrest you as a spy!" Instantly the armed guard surrounded the prisoner. "By Jove! This is great--absolutely!" he exclaimed, bursting into a roar of laughter. "Count who? You silly juggins, it's you who'll have to count, I guess! Quit fooling, and don't be a silly ass!" The armed party showed signs of incredulous astonishment. Canterbury looked at Derek as if he had been one of the victims of a practical joke. Even Daventry began to wonder whether he, too, had made a grievous error in placing the stranger under arrest. Then he nodded to the Orderly Officer in a manner that showed confidence in his action. "Carry on; remove the prisoner," ordered Lieutenant Canterbury. The formalities before the Adjutant having been completed, the accused, still protesting that it was all an idiotic mistake, was removed to the guard-room. On being subjected to a strict search--which resulted in the discovery of nothing of an incriminating nature--the prisoner was informed that he would be given facilities for proving his identity, and that no doubt some of his brother officers would appear to establish his innocence. Then, to the surprise of all present, the accused turned to Derek. "You are very smart," he remarked in quite a casual way. "I am Count von Peilfell. I should like to know how you spotted me?" "Considering that we were flying side by side a short while ago," replied Derek, "and you were making faces at me the whole time (perhaps you recollect the incident), I think I've good cause to recognize you again."