On and on they flew, changing their height occasionally, and, when they were fired at, which was the case not infrequently, they “zoomed” to escape the flying shrapnel.
But on the whole, they fared very well, and in a comparatively short time they found themselves over the country where, on the maps, was marked the location of Harry Leroy's prison camp.
“There it is!” suddenly exclaimed Tom, but of course Jack could not hear him. However, a punch in Jack's back served the same purpose, and he took his eyes from his instruments long enough to look down. Then a confirmatory glance at the map made him agree with Tom. The air service boys were directly over the prison camp.
This, like so many other dreary places set up by the Germans, consisted of a number of shacks, in barrack fashion, with a central parade, or exercise ground. About it all was a barbed wire stockade and, though the character of these wires did not show, there were also some carrying a deadly electric current.
This was to discourage escapes on the part of prisoners, and it succeeded only too well.
But the camp was in plain sight, and in the central space could be seen a number of ant-like figures which the boys knew were prisoners.
Whether one of them was Leroy or not, they were unable to say.
But they had reached their objective, and now it was time to act. High time, indeed, for below them batteries began sending up shells which burst uncomfortably close to them. They were of all varieties, from plain shrapnel to “flaming onions” and “woolly bears,” the latter a most unpleasant object to meet in mid-air.
For the Germans were taking no chances. They knew the vulnerable points of their prison camp lay above, and they had provided a ring of anti-aircraft guns to take care of any Allied, machines that might fly over the place. Whether any such daring scheme had been tried before or not, Tom and Jack could not say.
Of course it was out of the question that any great damage could be done in the vicinity of the camp without endangering the inmates, so it was not thought, in all likelihood, that any very heavy air raids would have to be repelled. But in any case, the Huns were ready for whatever might happen.