"I don’t care about that. Uncle beat off an attack once, and if those fellows want the mine, by Jove! they shall have a fight for it." "You’re talking through your hat," said Lawrence, whose tastes and temperament were quite unmilitary, and who did not know his brother, perhaps, as well as might have been expected. "Well, we’ll get back, at any rate," rejoined Bob, ignoring the accusation. "And, if possible, without being seen." They got up, and set off up-stream at a run, keeping as near as possible to the left-hand side of the track in order to escape observation. Only now did they discover how far they had come. The bridge was quite out of sight. They had not timed their walk, and had no means of knowing how many yards or even miles they had to cover before they should reach the aeroplane. The distance was in fact more than two miles, and the Kalmucks were only three-quarters of a mile behind them. The roughness of the track lessened the horsemen’s advantage in being mounted; but the boys feared that, if they had been seen, the Kalmucks, pressing on the small, hardy ponies, accustomed to rough country, might overtake them before they had time to make good their escape across the river. They were not long left in doubt whether they had been seen and were being pursued. They had been bounding along a straight stretch of the track, perhaps half a mile in length. Before they gained the farther end of it they heard the shrill shouts of the Kalmucks rising above the droning bass of the river. As they turned the corner, and passed out of sight, the sharp crack of rifles followed them; but the pursuers had not dismounted to take aim and had fired a thought too late. The only effect of the shots was to make the boys increase their speed, for they knew that the ponies must rapidly gain on them over the straight and fairly level portion of the track which they had just left. They pushed on gamely, hugging the cliffside as closely as possible, but being forced sometimes to diverge towards the river by the nature of the path. They looked anxiously ahead for a sight of the ruined bridge, and felt the shock of dismay, when, catching a partial glimpse of it at last, they found that they had still at least a mile to go. The pursuers began to close in upon them. A scattered volley proved that they had again been seen. The Kalmucks were firing and loading as they rode--a mere waste of ammunition, as it might have seemed, but for an instant proof that these warriors of the steppes were no mean marksmen, even in full career. Bob’s cap was struck from his head, and he discovered only by the blood trickling down his neck that he had been wounded. Lawrence, glancing over his shoulder, saw that it would be quite impossible to reach the bridge before the pursuers came up with them. "We can’t do it!" he gasped.