It was empty.
Had some person been listening, and had that person retreated in time to escape discovery?
The open door of the smoking-room showed that room also to be empty.

A third door was open--the door of the side hall, leading into the grounds.

Julian closed and locked it, and returned to the dining-room.
"I can only suppose," he said to Mercy, "that the billiard-room door was not properly shut, and that the draught of air from the hall must have moved it." She accepted the explanation in silence.

He was, to all appearance, not quite satisfied with it himself.

For a moment or two he looked about him uneasily.