Three resounding raps were struck upon the door.
At that, terror had no darker meaning for Cairn; he had plumbed its ultimate deeps; and now, like a diver, he arose again to the surface.
Heedless of the darkness, of the seemingly supernatural means by which it had been occasioned, he threw open the door and thrust his revolver out into the corridor.
For terrors, he had been prepared—for some gruesome shape such as we read of in The Magus. But there was nothing. Instinctively he had looked straight ahead of him, as one looks who expects to encounter a human enemy. But the hall-way was empty. A dim light, finding access over the door from the stair, prevailed there, yet, it was sufficient to have revealed the presence of anyone or anything, had anyone or anything been present.
Cairn stepped out from the room and was about to walk to the outer door. The idea of flight was strong upon him, for no man can fight the invisible; when, on a level with his eyes—flat against the wall, as though someone crouched there—he saw two white hands!
They were slim hands, like the hands of a woman, and, upon one of the tapered fingers, there dully gleamed a green stone.
A peal of laughter came chokingly from his lips; he knew that his reason was tottering. For these two white hands which now moved along the wall, as though they were sidling to the room which Cairn had just quitted, were attached to no visible body; just two ivory hands were there ... and nothing more!
That he was in deadly peril, Cairn realised fully. His complete subjection by the will-force of Ferrara had been interrupted by the ringing of the telephone bell But now, the attack had been renewed!
The hands vanished.
Too well he remembered the ghastly details attendant upon the death of Sir Michael Ferrara to doubt that these slim hands were directed upon murderous business.