All at once Jack saw some bulky object pass between their machine and the ground below. It must be the missing bomber, he concluded, though the realization of the fact made him thrill all over in admiration of the nerve of those who could accept such terrible chances.
Yes, despairing of getting in a telling blow at such a height, the reckless crew of the big Yankee plane had actually dropped down until they could not be more than a thousand feet from the earth. And now they were speeding forward, meaning to test their skill at such close quarters.
Not being able to make Tom hear his voice, Jack gave the other a tug, and so managed to call his attention to what was passing below. Just in time did Tom look, for at that very moment there came another of those amazing brilliant illuminations, and the dull roar greeted their ears a few seconds afterwards.
They saw with staring eyes the air filled with the material that had once constituted the wonderful bridge, across which day and night the retreating Huns were taking their valuable guns and stores. A brief space of time did the scene bear the aspect of chaos, and then, when the smoke cleared sufficiently for them to see, they looked upon a void where the bridge had stood.
Jack fell back appalled, yet quivering with deepest satisfaction. Their raid would be one of triumph, since the main object had now been achieved.
Hardly had he allowed himself to exult after this fashion than Jack discovered that Tom seemed to be greatly agitated. So he once more looked down, filled with a sudden fear lest the gallant fighters in that adventurous bomber had paid dearly for their success.
He immediately saw that his alarm was not groundless. The big Yankee plane must have been struck in some vital part, for it was rapidly sinking as though doomed. Jack's only consolation lay in the fact that the crew seemed to be in better luck than those of the stricken Gotha; for they managed to keep from turning turtle; and unless striking the ground with too great violence might yet come out of the affair alive, even though finding themselves prisoners of war.
Tom was already striking for the upper levels. He saw that the other three bombers had also commenced to climb, since their mission was now carried out, and further risks would be only a needless hazard. Then, too, the crews of the battle Gothas, realizing that they had failed to save the bridge, concluded to withdraw from the combat, leaving the Americans to make their way back to their starting point, victorious and rejoicing.
Yes, there was the signal flashing from the plane of the commander, which meant that the raiding squadron should assemble above the reach of the crackling shrapnel, and prepare in a body for the homeward journey.
A sense of exultation, mingled with sincere thankfulness, gripped the hearts of the two Air Service Boys as they realized that the peril was now really a thing of the past. The homeward trip would be a mere bagatelle, for surely no Huns would venture to attack them while on the way. By exercising good judgment they ought also to keep above the reach of those elevated anti-aircraft guns along the front hills.