There was a gasping sound, and the Mephistophelean man reeled, tried to save himself, and fell against the consulting-room door, which somehow flew open, revealing the sleeping figure of Mark Heath on the couch.

“My dear sir—faint?”

“I beg your pardon, doctor,” said the sinister-looking man. “Sick as a great girl. I can bear pain, but to see him like that turned me over. No, no, see to him; I’m better now.”

The doctor continued his task, while the door swung to once more.

“Still feel faint?” said the doctor, without looking up.

“Oh, no; it’s all gone now. I really am ashamed.”

“Nothing to be ashamed of, my dear sir. It is a man’s nature. Now I shall be obliged to ask one of you to lend me a little assistance here.”

The bearded man stood ready, and exchanged a glance with his Mephistophelean companion, who was behind the doctor now.

“Ah!”

Dr Chartley uttered a quick ejaculation, for, as he bent over his patient, the man behind struck him a heavy blow with a short thick life-preserver, and, quick almost as lightning, delivered another crashing stroke on the back of the head.