"It is empty, certainly," replied Dr. Cairn grimly, "or that apartment known as the King's Chamber is now empty. But even the so-called King's Chamber was not empty once; and there is another chamber in the pyramid which is not empty now!"
"If you know of the existence of such a chamber, sir, why have you kept it secret?"
"Because I cannot prove its existence. I do not know how to enter it, but I know it is there; I know what it was formerly used for, and I suspect that last night it was used for that same unholy purpose again—after a lapse of perhaps four thousand years! Even you would doubt me, I believe, if I were to tell you what I know, if I were to hint at what I suspect. But no doubt in your reading you have met with Julian the Apostate?"
"Certainly, I have read of him. He is said to have practised necromancy."
"When he was at Carra in Mesopotamia, he retired to the Temple of the Moon, with a certain sorcerer and some others, and, his nocturnal operations concluded, he left the temple locked, the door sealed, and placed a guard over the gate. He was killed in the war, and never returned to Carra, but when, in the reign of Jovian, the seal was broken and the temple opened, a body was found hanging by its hair—I will spare you the particulars; it was a case of that most awful form of sorcery—anthropomancy!"
An expression of horror had crept over Robert Cairn's face.
"Do you mean, sir, that this pyramid was used for similar purposes?"
"In the past it has been used for many purposes," was the quiet reply. "The exodus of the bats points to the fact that it was again used for one of those purposes last night; the exodus of the bats—and something else."
Sime, who had been listening to this strange conversation, cried out from the rear:
"We cannot reach it before sunset!"