Rising as quickly as possible, he held on his course, and in half a minute flew directly over the Kalmucks, and came in sight of the reach of the river beyond the bend. As he searched the banks, running the gauntlet of a fusillade, he was conscious of a feeling of dismay. For a full mile the river bank appeared to have been turned into a Kalmuck encampment. At irregular intervals above and below the winding track, the hill-side was dotted with tents and akois. Advantage seemed to have been taken of every square yard of level space to erect these portable shelters, which could be put up and taken down within a few minutes. It was clear that he had to reckon, not merely with the small party who had pursued him up-stream, but with a much larger number who had come up from the distant encampment during the previous afternoon and night. Horses were grouped wherever there was standing room for them. On the track and about the tents men were gathered, all gazing up into the sky, some taking shots at the aeroplane as it flew over them. It was flying swiftly, however, and with a vertical as well as a horizontal movement, so that even a practised sportsman, accustomed to shoot birds on the wing, could scarcely have hit his mark. Bob heard two or three bullets whistle past, but none struck the aeroplane or either of its occupants. Having seen so much, he determined to pursue his reconnaissance down the valley; it would be worth while to see if the camp on the plateau had been struck, for he would then be sure that the mine was indeed the objective of this force, and as he flew back be able, perhaps, to estimate its size. For the next few miles only a few straggling horsemen were visible, riding slowly up-stream. Then for a mile or two the track was bare, and he suspected that the men he had last seen were the rear of the enemy’s force. Still flying on, he came at length to the place where the valley broadened, and finally to the plateau which had been the limit of his flight on the day before. Here he swept round several times in ever widening circles, carefully scanning the ground. The camp had completely disappeared. Thinking that in so wide an area the small object which the encampment would present at so great a depth might escape his notice, he wheeled again and again, until he assured himself that no trace of it was discoverable. Then he was setting his course to return to the valley, looking southward to pick up his bearings, when there was a sudden shout from the Gurkha. He glanced round: the man was pointing excitedly to the north-west. Slowing down a little, but without altering his course, Bob looked in the same direction. The country was now bathed in sunlight; the air was clear; but he could perceive nothing to account for his companion’s excitement. He had faith enough in the man’s intelligence, however, to wheel round once more, and steer away from the valley. "What is it, Fazl?" he asked.