Bob said nothing. His mouth hardened, and he looked intently ahead. At a few yards’ distance a jutting rock encroached upon the track, rendering it only just wide enough for a horseman to pass. On rounding it he halted. "Down on the ground!" he panted. "Out with your revolver! There’s nothing else for it." They threw themselves down with their faces to the enemy, and covering themselves as well as they could with the corner of the rock, they held their revolvers ready to fire at the foremost of their pursuers. "Wait till they are within a few yards of us," said Bob. "No good wasting shots at long range. They are bound to go slow." They waited in breathless excitement. Lawrence the pacific was now as warlike as Bob himself. The enemy drew nearer. The narrowing of the track caused them to reduce their pace from a gallop to a trot, then to a walk. In the ardour of the chase their order had been changed; Black Jack was no longer in front. The boys had just had time to pull themselves together when the first man came within range. "Now!" said Bob, springing to his feet. Showing themselves on the narrow path between the rock and the brink of the river they emptied four barrels rapidly, almost pointblank at the horsemen. The first two men dropped; the others, taken utterly aback, reined up, but were thrown into a huddled mass by the men pressing on behind. There was a moment’s pause--a pause emphasized by cries of pain and fear, and the shrill screams of horses. Then the confused throng began to wheel about. "Hold your fire!" whispered Bob, at the same moment emptying his two remaining barrels into the medley. Another man fell. It was enough. Reckless of everything but his own safety, each man urged his steed back along the track, and in a few moments all had passed out of sight. "We win the first trick," said Bob, glancing at his brother. "Why, you’re as pale as a ghost!" "So are you," returned Lawrence. "Well, it’s our first experience of war, so I’m not surprised. But we must cut it. For one thing, my revolver’s empty, and I’ve no more cartridges here. For another, those fellows will come back as soon as they’ve got over their surprise, and even if they funk a frontal attack, I dare say they can manage to clamber round somehow and turn our flank. Our only chance is to make a break for the bridge and get over if we can before they’re fit to come on." [Illustration: A CHECK IN THE PURSUIT]