''The Figure of Eight'' (1931) by Cecil Waye (John Rhode/Miles Burton) is a 1930s thriller featuring private investigator Christopher Perrin. It focuses on international intrigue, starting with the mysterious, non-violent death of a woman on a London bus, which leads to a plot involving murdered diplomats, stolen documents, and a sinister secret society. A woman, later identified as Lola Martinaes, is found in an unshakeable, fatal sleep on a bus. Christopher Perrin, a private investigator (similar in style to Sherlock Holmes), investigates the murder of a diplomat and uncovers a wider conspiracy. More of a thriller than a traditional "whodunit," it features rapid action, exotic poisons, and a plot that moves from a murder mystery to espionage.