Loud and angry voices announced the fact that Carl Potzfeldt had arrived close enough to get a view of the rising plane in the misty light of the moon.
"Stop! I command you! Stop!" roared the German. And then came the crack! crack! crack! of firearms.
The air service boys, because of the noise of the motor, did not hear the discharge of the pistols, but suddenly Jack heard the spatter of a bullet as it struck the machine close beside him. Then he ducked and made a motion to Tom to let his chum know that they were under fire.
But the machine was gaining headway rapidly, and presently they were so high that those below could no longer reach them. Up and up they went until they were thousands of feet above the valley that had been the scene of this remarkable adventure.
Tom headed back along the course he had just come. It was now easy to pick up one landmark after another, and in due course of time they passed over the lines once more. Of Course, the sound of the plane's propellers was heard by the Germans, and some shrapnel was sent after them; but as Tom was careful to keep high in the air, this did not reach them, and soon they were out of the danger belt.
