Where was he going? He had not the most remote idea as to where Isabel was staying, and maddened by his position, he forced himself to go up to the drawing-room and ask his sister for the address.

“I must be half mad,” he muttered.

He threw open the drawing-room door and, strode in, determined to insist upon the address being given him if Laura should refuse.

But the room was empty, and, staggered by this fresh surprise and with ominous thoughts beginning to arise, he went out on to the landing to call his sister by name. Then he called aloud to his aunt, with the result that an answer to his shouts came from below in the servant’s voice—

“Beg pardon, sir; Miss Laura and Mrs Crane went out more than an hour ago.”

“What! Where did they go?”

“I don’t know, sir. I had to whistle for a cab, and they each took a travelling bag.”

Chester went down to his consulting-room, checkmated, and feeling completely stunned at his position.

What was he to do? He might set a detective to try and find the cabman who took them away, but it would be days before he could have the man traced.

Then came a bright idea.