Bob lighted a cigarette, and paced up and down, thinking hard. If only Major Endicott or some other experienced soldier were at hand to advise! He felt weighed down by his responsibilities; yet beneath all his anxieties, there was a large reserve of courage and resolution. He watched the Sikhs dragging the machine gun across the compound. Undoubtedly it would check the Kalmucks as they marched back towards the mine. But he wondered whether it would be wise to use it. It would cost many lives; the slaughter of the miners would infuriate their fellow-countrymen, and destroy any chance there might be of making terms with them. Yet there seemed no other means of assuring his brother’s safe return. Following in imagination the pursuit along the river bank, he thought of the Pathans and their fate. He listened for rifle-shots; but the sounds had ceased. By this time, no doubt, the chase had gone beyond hearing. Perhaps it had ceased; perhaps the Pathans were all slaughtered by their more numerous foes; perhaps the Kalmucks were content to have driven them away, and the survivors were trudging a weary march to the borders of their own land. What would their fate be? They had no food: the country was barren: they must surely fall a prey to fatigue, exposure and famine, or to hostile tribes _en route_, long before they could hope for hospitality. This dismal prospect made Bob very uncomfortable. After all, these men were the most loyal and law-abiding of his uncle’s workers; it seemed cruel to let them go without lifting a hand to help them. Yet what could he do? No doubt if he were to lead the Sikhs to pursue the Kalmucks in their turn, with their military training, few as they were, they might crush the undisciplined rabble. But he dared not thus leave the mine ungarrisoned. It would be long, indeed, before the Kalmucks could arrive from the north unless the unexpected happened; but so many unexpected and inexplicable things had happened during the last twenty-four hours that he could not take any action that would involve risk either to Lawrence or to the non-combatants at the mine. As he paced to and fro, watching the Sikhs going quickly about their work, and the servants returning over the drawbridge, laden with what they had gathered from the miners’ quarters, it occurred to him suddenly that if only the aeroplane were equipped for war some of his difficulties would be solved. He had intended to qualify for the aerial corps in the British army, but that dream was over: flying had been to him merely a sport. Could he have foreseen the strange circumstances of the last few days, he would have adapted his machine, not merely for pleasure trips and observation, but for actual offence.