not realize what had happened until he heard a click again. The light was suddenly flashed on him, level with his eyes.
"You can't see me," said a mocking voice, "I'm looking at you through the little spy-hole. Did you see the spy-hole, clever Mr. Beale? And I am on the other side of the door." He heard her laugh. "Are you going to arrest the doctor to-night?" she mocked. "Are you going to discover the secret of the Green Rust—ah! That is what you want, isn't it?"
"My dear little friend," said Beale smoothly, "you will be very sensible and open that door. You don't suppose that I came here alone. I was shadowed all the way."
"You lie," she said coolly, "why did I dismiss the cab and make you walk? Oh, clever Mr. Beale!"
He chuckled, though he was in no chuckling mood.
"What a sense of humour!" he said admiringly, "now just listen to me!"
He made one stride to the door, his revolver had flicked out of his hip-pocket, when he heard the snap of a shutter, and the barrel that he thrust between the bars met steel. Then came the grind of bolts and he pocketed his gun.
"So that's that," he said.
Then he walked back to the other door, struck a match and examined it. It was sheathed with iron. He tapped the walls with his stick, but found nothing to encourage him. The floor was solidly flagged, the low roof of the passage was vaulted and cased with stone.
He stopped in his search suddenly and listened. Above his head he heard a light patter of feet, and smiled. It was his boast that he never forgot a voice or a footfall.
"That's my little friend on her way back, running like the deuce, to tell the doctor," he said. "I have something under an hour before the shooting starts!"
