A gripping crime novel from a master crime writer. This novel features interesting characters, locked rooms, cellars, several deaths, along with other crimes. The novel is mostly set in or near London along with some more exotic locations. The main character is a Scotland Yard detective who uses his own methods (sometimes outside the law) and vast knowledge to solve crimes. The plot has many twists and turns and working out who did what and why is only part of the fun - how it was done is the real mystery.