About the book: year / It happened last night, just after dinner. The door was locked from the inside. Both French windows were double shuttered on the inside, although the curtains were not drawn. There was no one in the room except them, no one was hiding there. There is no other entrance to the room. The revolver lay near the colonel's right hand. No one touched the valves or latches. The room was closed like a fortress. These are the facts, Mr. Holmes.