Bob found it by no means easy to follow a course that would enable his passengers to obtain a clear view of the more rugged portions of the valley. Here and there, at the wider parts, he was able to wheel round and cover wide areas; but in the narrow stretches he was forced to fly straight ahead without the possibility of turning, unless he should rise to a great height. This would involve a loss of time which could be ill afforded. Once or twice, in attempting to circle, he almost shaved the rocky sides; and deciding that such attempts were too dangerous, he concluded that he had better leave certain parts imperfectly explored rather than risk injury to the aeroplane. He compromised matters by steering a serpentine course, thus covering as much as possible of the ground on both sides of the river. The aeroplane was approaching the rope bridge when Mr. Appleton suddenly called out that he saw two men on horseback on the track beyond. In another moment he recognized them through his glass as the men of whom they were in pursuit. They were nearly a mile distant, entering a stretch of the gorge that was particularly rugged, and no doubt afforded plenty of cover. It had been prearranged that as soon as the men were sighted Bob should make a descent as near as possible ahead of them--that is, down-stream--but it was no surprise to Bob--indeed, it was only according to the ill-luck that seems to rule on such occasions--that no suitable landing place offered itself. He remembered, however, that in flying downstream he had noticed, two or three miles above the bridge, a place where the valley widened sufficiently to allow the aeroplane to circle. He decided to fly direct to this spot, turn, follow the men, outstrip them, and land at a spot some distance down-stream, where a landing had seemed feasible. Lawrence suggested that he or his uncle should take a flying shot at the men as they passed above them, but Mr. Appleton would not consent. "Punishment before trial won’t do," he said. By this time the fugitives had disappeared behind a sort of parapet of rock just above the bridge, which spanned the river at a height of twenty or thirty feet. On first sighting them, Bob had caused the aeroplane to descend until it was almost level with the bridge. As they came to it, Mr. Appleton rose in his seat behind the pilot, to see, if he could, the precise spot in which the fugitives had concealed themselves. He had just done so, and was leaning slightly to the right, when there came in rapid succession the crack, crack of two rifles. And then Lawrence, in the third seat, was horrified to see his uncle pitch forward, lose his grip on the stay he was clutching, and fall headlong into the river. It all happened so instantaneously that the boy had no time even to reach forward. He sprang up, almost over-balancing himself, but before he could stretch out his hand Mr. Appleton was whirling in mid-air.