"Do all these doors open upon rooms similar to this?" asked T. B.

"I believe there are a number of underground cells," she answered in a whisper, "but the principal one is that which is near." She pointed to a red-painted door some twenty paces away from the one from which they were emerging. There was another pause whilst Ela repeated his examination of the door.

Apparently they all worked on the pick system, a method which medieval conspirators favoured, and which the Italian workmen probably imported from the land of their birth; a land which has given the world the Borgias and the Medicis and the Visconti.

"Stay here," said T. B. in a low voice, and Lady Constance shrank back against the wall.

Ela pressed in his little needle and again the result was satisfactory. The door opened slowly and T. B. stepped in.

He stood for a moment trying to understand all that the terrible scene signified. The limp body on the floor; the two remorseless men standing close by; Farrington with folded arms and his eye glowering down upon the dead man at his feet. Fall at the switchboard.

Then T. B.'s revolver rose swiftly.

"Hands up!" he said.

The words were hardly out of his mouth when the room was plunged in darkness, his companion was flung violently backward as the electrical control came into operation and the door slammed in Ela's face. He pressed it without avail. He brought to his aid the little needle, but this time the lock would not move.

Ela's face went chalk white.