He heard the bell of St. Paul's strike ten and eleven. The last stroke had scarcely ceased to vibrate when he rose to his feet suddenly. He heard, on his left, a scraping noise. A moment later it ceased, and then was renewed again. It lasted but a few seconds; then he heard an irregular, shuffling noise, that seemed to him upon the roof of the warehouse. Pressing his face to the casement, he suddenly became aware that the straight line of the ridge was broken by something moving along it, and a moment later he made out a second object, just behind the first. Moving with the greatest care, he made his way out of the room, half closed the door behind him, crossed the passage, and pushed at a door opposite.

"Captain Dave," he said, in a low voice, "get up at once, and please don't make a noise."

"Ay, ay, lad."

There was a movement from the bed, and a moment later the Captain stood beside him.

"What is it, lad?" he whispered.

"There are two figures moving along on the ridge of the roof of the warehouse. I think it is the apprentices. I heard a slight noise, as if they were letting themselves down from their window by a rope. It is just over that roof, you know."

There was a rustling sound as the Captain slipped his doublet on.

"That is so. The young scoundrels! What can they be doing on the roof?"

They went to the window behind. Just as they reached it there was a vivid flash of lightning. It sufficed to show them a figure lying at full length at the farther end of the roof; then all was dark again, and a second or two later came a sharp, crashing roar of thunder.

"We had better stand well back from the window," Cyril whispered. "Another flash might show us to anyone looking this way."