“We were all sent to a place in France known as the Pool Pilots’ Mess. Here men gather from all the training squadrons in Canada and England and await assignments to the particular squadron of which they are to become members.” He was soon “called” to a squadron stationed about eighteen miles back of the Ypres Line. There were eighteen pilots. The routine was two flights a day, each of two hours’ duration. He presently found that his squadron “was some hot squadron,” the fliers being assigned to special-duty work, “such as shooting up trenches at a height of fifty feet from the ground.” CAPTURED BY THE HUN Pat holds August 17, 1917, as a day he will “not easily forget.” He has fairly good reason for thinking the day a fixity in his memory, for, as he says: “I killed two Huns in a double-seated machine in the morning, another in the evening, and then I was captured myself. I may have spent more eventful days in my life, but I can’t recall any just now.” Considering the fact that he had been shot down from a height of 8,000 feet the miracle is that he became “a prisoner of war.” His fellows of the squadron who had seen the fight took it as a matter of fact that he had been killed outright. One realizes that a chap who could come through that sort of juggle with death was quite equal to his later adventures. Convalescent, after some time spent in a hospital, O’Brien was sent to the officers’ prison camp at Courtrai, preparatory to transfer to a prison in the interior of Germany. He remained there nearly three weeks, to which he devotes an interesting chapter. He had many fellow prisoners, and, of course, one frequent topic of conversation was “what were the chances of escape?” There were many ingenious plans but O’Brien did not remain to attempt to carry out any of them. September 9th he and six other officers were marked off for transfer into Germany, and later were marched to the train that was to convey them. They were objects of derision to the crowd gathered at the station. There were twelve coaches, eleven of them containing troops going home on leave, the twelfth, fourth class, filthy, being reserved for the prisoners, eight of them under four guards. He proposed to the other officers that if the eight of them would at a given signal jump on the four guards and overpower them, they could, when the train slowed down on approaching a village, leap to the ground and take to flight. But the others turned the plan down on the ground that if they did get free they would be recaptured speedily. O’Brien therefore resolved to make a try on his own account by a leap from a window when the train was in motion. After long self-debate, as they were getting nearer and nearer to their destination he successfully put his resolution into effect. MAKING HIS ESCAPE