Either he was become again a victim of the strange trickery which already had borne him, though not physically, from Fleet Street to the secret temple of Méydûm, or with his material senses he had detected a soft rapping upon the door of his room.
He knew that his outer door was closed; he knew that there was no one else in his chambers; yet he had heard a sound as of knuckles beating upon the panels of the door—the closed door of the room in which he sat!
Standing upright, he turned deliberately, and faced in that direction.
The light pouring out from beneath the shade of the table-lamp scarcely touched upon the door at all. Only the edges of the lower panels were clearly perceptible; the upper part of the door was masked in greenish shadow.
Intent, tensely strung, he stood; then advanced in the direction of the switch in order to light the lamp fixed above the mantel-piece and to illuminate the whole of the room. One step forward he took, then ... the soft rapping was repeated.
"Who's there?"
This time he cried the words loudly, and acquired some new assurance from the imperative note in his own voice. He ran to the switch and pressed it down. The lamp did not light!
"The filament has burnt out," he muttered.
Terror grew upon him—a terror akin to that which children experience in the darkness. But he yet had a fair mastery of his emotions; when—not suddenly, as is the way of a failing electric lamp—but slowly, uncannily, unnaturally, the table-lamp became extinguished!
Darkness.... Cairn turned towards the window. This was a moonless night, and little enough illumination entered the room from the court.