Roque, as usual, wherever he went or wherever he was, seemed to carry an Aladdin magic carpet on which to sail, for in the next flight of the biplanes a few miles distant he found a bright spot in this winter scene of rack and ruin--a clean, white lodgekeeper's kitchen, where a canary sang, and where the aërial wayfarers rested and were fed. "I'll show you even better," he said, "when we break into Warsaw." The chief also had a particular crow to pick with the defenders of the Polish capital. One of his men, for some time operating with the Russians, had been detected, and the end of a story of brilliant secret service achievement was marked by a little mound of earth in a Warsaw stable yard. But for the present there were busy days ahead for the aviators in reconnoitering the Russian lines. Most of the aërial work here was over a plain, flat as a floor. Black dots here and there marked isolated houses, and the Kalish road was bordered by a line of leafless trees with smooth trunks, which reminded the young pilots of a rank of grenadiers. "What's that bunch over there?" queried Billy, nodding toward a group of horsemen, shrouded in long caftans, wearing lambskin caps shaped like a cornucopia, and bearing lances. "They are Cossacks," replied Roque, from the observer's perch, "the strange fighters who never surrender." Billy had later an opportunity for closer view of these reckless riders in the service of the Czar. The flyers could see that the road below was this day crowded with the carts of refugees, trailing in endless procession, on the top of each vehicle the members of the family, the average one man to five women. The boys noted that there were not so many children here as they had seen among the homeless wanderers in Belgium. The same problem was here, however--what are they going to do? "There they go again," cried Henri, referring to renewed outbreak from the long gray noses sticking out over the top of a brown gun emplacement--belching cones of death, and shooting red flare into the gray-white atmosphere. Then another noise out of the winter-worn copse of trees--pop, pop, pop, the notes of rifle fire, all raising a queer mist over the plain. With all this racketing no soldier could be seen at the point of fire. If trouble was contagious, the biplane Henri was driving suddenly caught some of it; something went wrong with the motors, and it was a case of get down quick in the long slide, in which performance the young pilot excelled. He landed safely enough, but without choice of place. The machine was stranded in Sochaezev, a city of the dead. Pale faces were still peering from some of the doors and windows, though almost every roof had been battered in, leaving only the stringers, reminding one of skeletons. Billy had instantly volplaned in pursuit of the disabled biplane of his partner, and the two experts, assisted by Schneider, were speedily at the work of repair.