The more Bob thought of all this, the more anxious and depressed he became. He wondered whether it was wise to attempt to stem the human torrent that would soon be pouring up the valley. Would not the better course be to come to terms with the Kalmucks, abandon the mine, and set off with all speed for India? Hitherto, it was true, the enemy had given him no opportunity for negotiating. They had been the aggressors, unprovoked; and his determination hardened when he remembered the fate of Mr. Appleton. But as there was just a possibility that no sort of concert existed between the Kalmuck army and Nurla Bai, the idea of making terms with the former was not wholly negligible. So far as his immediate duty was concerned, Bob was quite clear in his mind. It was to secure the retreat of Lawrence and his little party. In order to reach the mine they would have to pass the quarters of the Kalmuck miners. The bridge down-stream being broken, Bob could not suppose that Lawrence would be so hotly pursued as to endanger his return. But with temper high among the workers at the mine, some care might be needed to prevent an explosion when the Pathans came up. The first thing to be done was to devise some means by which Lawrence and his men could reach the settlement in safety. Allowing for the difficulties of the track, they could hardly, even though mounted, arrive until late in the afternoon. He had the whole day in which to make his preparations. Bob did not think out the position as consecutively as his thoughts are presented here. His busy mind flitted from one point to another doubling on itself, as it were. And his reflections were suddenly interrupted by an exclamation from his companion. The Gurkha, having no mental puzzles to work out, had been able to give undivided attention to his master’s instructions. As before, his keener eye had detected what Bob, even if less preoccupied, could scarcely have perceived so soon. Far ahead, over the valley, there lay a long dark streak which in a less clear atmosphere than that of this highland region might have been taken for a wisp of cloud. But Fazl made no such mistake. "Smoke, sahib!" he cried. The words gave Bob a shiver of apprehension. Was it possible that the mine-buildings were on fire? He felt almost overwhelmed at the thought. With every succeeding second in his swift flight it became more and more likely that this was the explanation. While still many miles distant, he recognized that the smoke must have its origin somewhere at least in the neighbourhood of the mine. Fast as the aeroplane was flying, he wished that for a few minutes he could double its speed. But when at last he opened up the reach of the river bordering the mine, he saw with joy that the smoke was rising, not from the compounds on the right, but from the miners’ quarters on the opposite bank.