"The Mask of Dimitrios" is a novel written by Eric Ambler, first published in 1939. The story follows a British writer named Charles Latimer who becomes intrigued by the mysterious life and death of a criminal named Dimitrios Makropoulos. As Latimer investigates, he uncovers a web of espionage, deceit, and danger that leads him through various European cities. The novel is notable for its exploration of themes such as identity and morality, set against the backdrop of the pre-World War II era. It combines elements of a thriller and a detective story, showcasing Ambler's skill in creating suspenseful narratives that reflect the complexities of human nature.