"The camp was situated on the slope immediately below the only _known_ entrance to the Meydum Pyramid; one might say that it lay in the shadow of the building. There are tumuli in the neighbourhood--part of a prehistoric cemetery--and it was work in connection with this which had detained Ali Mohammed in that part of the Fayum. Last night about ten o'clock he was awakened by an unusual sound, or series of sounds, he reports. He came out of the tent into the moonlight, and looked up at the pyramid. The entrance was a good way above his head, of course, and quite fifty or sixty yards from the point where he was standing, but the moonbeams bathed that side of the building in dazzling light so that he was enabled to see a perfect crowd of bats whirling out of the pyramid." "Bats!" ejaculated Robert Cairn. "Yes. There is a small colony of bats in this pyramid, of course; but the bat does not hunt in bands, and the sight of these bats flying out from the place was one which Ali Mohammed had never witnessed before. Their concerted squeaking was very clearly audible. He could not believe that it was this which had awakened him, and which had awakened the ten or twelve workmen who also slept in the camp, for these were now clustering around him, and all looking up at the side of the pyramid. "Fayum nights are strangely still. Except for the jackals and the village dogs, and some other sounds to which one grows accustomed, there is nothing--absolutely nothing--audible. "In this stillness, then, the flapping of the bat regiment made quite a disturbance overhead. Some of the men were only half awake, but most, of them were badly frightened. And now they began to compare notes, with the result that they determined upon the exact nature of the sound which had aroused them. It seemed almost certain that this had been a dreadful scream--the scream of a woman in the last agony." He paused, looking from Dr. Cairn to his son, with a singular expression upon his habitually immobile face. "Go on," said Robert Cairn. Slowly Sime resumed: "The bats had begun to disperse in various directions, but the panic which had seized upon the camp does not seem to have dispersed so readily. Ali Mohammed confesses that he himself felt almost afraid--a remarkable admission for a man of his class to make. Picture these fellows, then, standing looking at one another, and very frequently up at the opening in the side of the pyramid. Then the smell began to reach their nostrils--the smell which completed the panic, and which led to the abandonment of the camp--" "The smell--what kind of smell?" jerked Robert Cairn. Dr. Cairn turned himself in his chair, looking fully at his son. "The smell of Hades, boy!" he said grimly, and turned away again.