“What happened in the interval between then and four o’clock?�

“I was searching through the house, and making the inquiries I told you about.�

“It required three-quarters of an hour to do all that?�

“That is the time I took for it, before I convinced myself that it would be wise to communicate with you, Mr. Carter.�

“What brought you to this room at a quarter to three?�

“It was the hour for Mr. Lynne’s tonic. He takes it every four hours.�

As Thomas made this statement he half turned toward a table across the room; then he gave a start, and uttered a quick exclamation.

“What is it?� asked the detective.

“The tonic is not here,� was the reply.

“The tonic? Gone, you say?�