They had emerged from a round-mouthed tunnel--it looked already like a rabbit-hole, so huge was the cliff behind--on to a ledge of rock that formed a sort of road along one side of a mile-wide chasm. Above him, it seemed a mile up, was blue sky, to which limestone walls ran sheer, with scarcely a foothold that could be seen. Beneath, so deep that eyes could not guess how deep, yawned the stained gorge of the underworld, many-colored, smooth and wet. And out of a great, jagged slit in the side of the cliff, perhaps a thousand feet below them, there poured down into thunderous dimness a waterfall whose breadth seemed not less than half a mile. It spouted seventy or eighty yards before it began to curve, and its din was like the voice of all creation. Ismail came and stood by King in silence, taking his hand, as a little child might. Presently he stooped and picked up a stone and tossed it over. “Gone!” he said simply. “That down there is Earth's Drink!” “And this is the 'Heart of the Hills' men boast about?” “Nay! It is not!” snapped Ismail. “Then, where--” But the one-eyed guide beckoned impatiently, and King led the way after him, staring as hakim or prisoner or any man had right to do on first admission to such wonders. Not to have stared would have been to proclaim himself an idiot. The least of all the wonders was that the secret of the place should have been kept all down the centuries; for it was the hollow middle of a limestone mountain, that could neither be looked down into from above, because the heights were not scalable, nor guessed at from the conformation of the country. The river, that flowed out of rock and went plunging down into the chasm, must be snow from the Himalayan peaks, on its way to swell the sea. There was no other way to account for that; but that explanation did explain why at least one Indian river is no greater than it is. The road they followed was a fold in the natural rock, rising and falling and curving like a ribbon, but tending on the average downward. It looked to be about two miles to the point where it curved at the chasm's end and swept round and downward, to be lost in a fissure in the cliff. They soon began to pass the mouths of caves. Some were above the road, now and then at crazy heights above it, reached by artificial steps hewn out of the stone. Others were below, reached from the road by means of ladders, that trembled and swayed over the dizzying waterfall. Most of the caves were inhabited, for armed men and sullen women came to their entrances to stare. Ears grow accustomed to the sound of water sooner than to almost anything. It was not long before King's ears could catch the patter of his men's feet following, and the shod clink of the mule. He could hear when Ismail whispered: “Be brave, little hakim! She loves fearless men.”