As I pondered over the past history of what I knew of this man, it all came vividly back to my mind. His smile as he saluted and passed along to the right to get his entrenching tool and the manner that he had said "enemy of ours" in the dining-room in Montreal. Suddenly on our right flank the Germans began to send up some red rockets and then a few golden sprays. Word was passed along to send up our S.O.S. I asked who had sent the message. The man to my right said he did not know. I then jumped out of the trench and walked along the parados. I found that five men from my right had received this message and the sixth man was Wagner, and the man next to him did not know anything about it. We act quickly at the front; we take no chances. I interrogated Wagner, but he disclaimed any knowledge of the message. I was not satisfied with this answer. Although I had known him so long, the various little incidents which had transpired during our association now firmly convinced me that he was a German. I immediately placed him under arrest with a strong guard over him, although I may say that I felt like killing him on the spot. If we had sent up our S.O.S. signal our artillery would have placed an intense bombardment on the German trenches along our sector of the line. While our artillery were busy shelling in this locality, the Germans would have attacked another point, where they would have encountered less opposition of artillery and in all probability broken through our line. It was a well-arranged scheme; but it failed, thank God. As soon as we stood down I had Wagner brought to my company commander. I made out a written report, detailing the whole circumstances of the affair. Wagner was searched and in the heel of a boot that he was wearing was found some very thin tissue paper, neatly folded. It did not appear to have any writing on it, but as we laid the paper on a small box in the company headquarters dugout, a candle was burning brightly, so we held it close to the light. We could make out a drawing of our trench. Apparently invisible ink had been used. As we continued to hold the paper before the candle, German writing gradually came to view. Judging from the expression on Wagner's face you would not have thought that his life was at stake. He appeared to be quite resigned to the fate that awaited him. It is customary for the army to have carrier pigeons. The pigeons are kept at certain points some distance in the back area of the trenches, where they are kept in large cotes until required by any particular unit. It sometimes happens that a company commander may require two pigeons to take with him into the trenches in order to send messages back to the rear. The message is fastened to the leg of the pigeon, and when the pigeon arrives at the cotes the message is taken off its leg and handed over to the signallers, who transmit the message to the proper authorities by wire or motor despatch riders.