Next morning we travelled twelve or thirteen miles, always under sheer scarped cliff, never a drop of water, never a sign of slope that we might climb. We moved eastward, since from far off it had seemed to me that the cliffs were lower that way. We had now but four days’ scanty water left, and the heat of the desert, even at this cold season, was causing some loss by sweating through the skins in which we carried it. Islam prayed me to start back forthwith making forced marches, but I was sure that water was to be found. Arslan, moreover, said that unless the camels could be fully watered they would die in the desert, and with them we also should perish, leaving our bones to whiten in the wastes of sand. So next day again we started early, and all day travelled below the unfriendly cliffs, but never finding water, until late in the evening the camels, which till now had been barely able to drag their lank limbs along, quickened their dragging pace; and presently Islam, who was on ahead, called out loudly to me. I hastened on to where he stood on a high rock, and saw before me a narrow valley opening into the cliff, and in the bed of the valley a little stream of clear water, and men and beasts drank their fill. The cleft at whose dark mouth we stood was narrow, a bare twenty paces wide, and with the same scarped sides of incredible height. It wound away into the cliff, already partly hidden in the evening dusk, though where we stood was yet lit with the sun’s last rays. Reassured now by our find of water, we settled us down for the night, and in the morning refilled all water-skins. The dawn light showed a few stunted bushes and a dwarf tree or two, but no sign of human beings. Leaving Arslan to tend the beasts, which found some scant grazing in the valley entrance, and taking Islam with me, I set about exploring the cleft. It got more and more narrow and darker and darker, until, after some three miles, we could touch the sides of smooth rock with our outstretched hands, but never, never a place that a man might climb. The cold was intense in this dark confined slit that knew the warm sun but for a brief space each day. Then, rounding a sudden corner, came we to the end. The narrow valley opened upon a circus perhaps two hundred paces in diameter, sheer cliffs around it. But oh! the wonder of that evil place. The valley closed again, and there before us, carved at the foot of the towering rock, was a gateway of old fashion with an inscription and a design of serpents upon it. But even more strange was the ground at our feet. For it was covered with bones of men.