"You are insolent, and you will be asked to prove your words," said the German in a threatening way. "Keep cool! Now, look here, this passport shows that you were in Germany at the time of mobilisation. It also shows that you were in France at the time that the advance was made on Paris. Can you explain?" "Of course, I was on business for my firm." "The Secret Service, eh?" "No, sir; again you insult me." "Very well; quick march." "I refuse." "Take him off," ordered Greens sternly to the escort. "Uh!" was the fierce exclamation of the baffled Teuton, stepping on with his guards. He was quickly placed under lock and key. In his bag Greens found correspondence in code, envelopes from a famous "firm" which always paid well for information, as well as a heap of notes and gold. A simple citizen and the ordinary policeman would have passed this man as innocent, but Greens found a clever Intelligence Officer who labelled this German as an Inspector of the Espionage System. He travelled around for his iron goods. He also called on his local "friends," and paid good cash for "services rendered," as many receipts in his possession showed. In a few words, Greens proved his contention that this man, like thousands more, was a spy, immune from arrest because of naturalisation,—a scrap of paper which ought to be ruthlessly burned and disregarded when found on any of German birth or origin. There was a smile on Greens’ face as he entered the mess-room that evening. "Why that smile?" inquired Longlegs. "The smile means champagne. Your spy is in the garrison guard-room, and to-morrow, no doubt, will find him interned for many a long day." "Cheer ho," yelled the subs, gathering round to hear the spy-hunting exploit. That was the last spy caught in Mudtown. The German Secret Service labelled it "Dangerous." If every policeman was as alert as Greens, all of these naturalised scoundrels would be under lock and key to-day. CHAPTER XV. A COMPANY OFFICER’S WORRIES.