Suddenly the hovering airmen got a signal, but not the expected flash of scarlet. One of the carters, a big fellow, rose from his seat and frantically waved his arms, and the boys were then so near that they could plainly see that he varied the queer performance by pointing skyward with the long whip he was holding. So intent had been the aviators in trailing the cart that they had neglected for a time to look elsewhere about them. The gestures of apparent warning that they were witnessing returned their wits to normal, and what they had from the first low flight feared was about to be realized. Barely a half mile away, and buzzing toward them, were three aëroplanes, which, unnoticed by the otherwise engaged lads, had risen from the Russian camp. Billy and Henri, now wholly confident that the antics that had awakened them to the impending peril were those of no other than Schneider, gave that good friend a parting salute of cap waving and turned about at full speed to lead a stern chase over and beyond the city--far beyond, it proved. The pursuing biplanes, of the largest type, carried a crew of three men each, and that they had tremendous motor power was evidenced by their catapult coming. But, light-weighted, the No. 3's were not to be easily overhauled. It must have been a contrary spirit that induced Billy and Henri to do other than head across the river to the German camp. They were in their element, however, and it was the kind of exploiting that most appealed to them. Keeping out of range of the guns of their armed pursuers was the first care, and no other care had the lads how long the chase continued. They would even hold, as a bait to keep the fun going. That grave consequences might follow capture was not at all an issue. The boys had no thought of aught else than that they were jockeying in an aëroplane race. How far afield they had driven they did not realize until with waning day they had outdistanced their pursuers. They were compelled to land in strange territory, for they feared to take the chance of exhausting the supply of petrol carried by the aëroplanes, and, besides, the continued strain on the aviators themselves was beginning to tell. "Oh, for a 'lodge in some vast wilderness,'" spouted Billy in actor style. He had a very pleasant memory of that lodgekeeper's kitchen, in which they, cold and hungry, had been warmed and fed. "I'd like mighty well," he added, "to hear that canary twitter right now." "Barring all that," remarked Henri, "we might be in a worse fix, considering that we have something to eat with us and a good pair of blankets for a bed." "I am not particularly impressed with these surroundings, though," argued Billy, "a swamp on one side, a bunch of stunted willows on the other, and a regular no man's land front and back." "Oh, quit your kicking, Buddy, and let's make the best of it." Henri started for the willows, in the hope of finding enough dry material to make a fire.