"It means," answered Cairn, in a low voice, "that my suspicion, almost incredible though it seems, was well founded. Steel yourself against the task that is before you, Sime; we stand upon the borderland of strange horrors."

Sime hesitated to touch any of the dead bats, surveying them with an ill-concealed repugnance.

"What kind of creature," he whispered, "has done this?"

"One of a kind that the world has not known for many ages! The most evil kind of creature conceivable—a man-devil!"

"But what does he want with bats' heads?"

"The Cynonycteris, or pyramid bat, has a leaf-like appendage beside the nose. A gland in this secretes a rare oil. This oil is one of the ingredients of the incense which is never named in the magical writings."

Sime shuddered.

"Here!" said Dr. Cairn, proffering a flask. "This is only the overture! No nerves."

The other nodded shortly, and poured out a peg of brandy.

"Now," said Dr. Cairn, "shall I go ahead?"