Adventure of the Red Circle

Mrs. Warren, a landlady, comes to 221B Baker Street with some questions about her lodger. A heavily bearded man, who spoke good but accented eng came to her and offered double her usual rent on the condition that he get the room on his own terms. He went out the first night that he was there, and came back after midnight when the rest of the household had gone to bed. Since then, neither Mrs. Warr...