The track was narrow and winding and full of mud, which fouled the horses and made the climbing doubly hard. It was quite dark there, but Piet knew every inch of the path, and rode on ahead fearless and confident. In about an hour they emerged. There were the lights of the British camp twinkling a mile and a half away. As they commenced the descent they heard a shot ring out, and Brenda gave a cry of dismay. Piet Bok had fallen from his saddle. "Ride, ride for your lives!" cried the old man. "He has come round by the other pass." And so it was. Van Zwieten, instead of following at their rear, had pushed through the other pass and had cut them off. But he had made one mistake. He had allowed them to get out of the pass on to the higher ground instead of cutting them off from the camp. As shot followed shot, Harold caught Brenda's horse by the bridle. Headlong they tore down toward the plain. The light, or rather the dark, was all against the pursuers. They gave up firing and made to overtake them. But the sound of the muskets had already been heard in the camp, and they could hear the bugles ringing out. Whether the brave old Boer who had saved them was dead or not they did not know. It was beyond their power to aid him. They urged their horses on and on, for in their speed lay the only hope of escape. "Courage, Brenda!" cried Harold. "Stick to it; they've heard the firing in camp." "I will, dear--I will." Then her husband looked round, and an exclamation of mingled relief and triumph came from him. They had given up the chase. "They've had enough of it, hurrah!" he cried. They were now within a short distance of the camp, and could hear the commands being given consequent on what evidently had been taken for the commencement of a surprise on the part of the Boers. Those behind them had turned and fled now in the opposite direction--all of them save Van Zwieten. He stood up and fired twice. But his shot fell wide. Then Harold turned and tried what his revolver would do at that range. Van Zwieten's arm fell useless. Then he galloped off, none too soon, for a squadron of mounted infantry came on the scene just at the moment. "What's all this?" shouted the captain in command. "We have escaped!" shouted Harold--"Burton and Mrs. Burton." "What, is it you, old man?" cried a friendly voice--a voice they knew well. For the fourth time Brenda had escaped her enemy. CHAPTER XXVII. NEMESIS.