Often typecast as a menacing figure, Peter Lorre achieved Hollywood fame first as a featured player and later as a character actor, trademarking his screen performances with a delicately strung balance between good and evil. His portrayal of the child murderer in Fritz Lang's masterpiece M (1931) catapulted him to international fame. Today, the Hungarian-born actor is also recognized for his riveting performances in The Man Who Knew Too Much (1934), The Maltese Falcon (1941), and Casablanca (1942). The first biography of this major actor, The Lost One: A Life of Peter Lorre draws upon more than three hundred interviews, including conversations with directors Fritz Lang, Alfred Hitchcock, Billy Wilder, John Huston, Frank Capra, and Rouben Mamoulian, who speak candidly about Lorre, both the man and the actor. Stephen D. Youngkin examines the enigmatic persona long associated with one of classic Hollywood's most recognizable faces, offering the definitive account of a life triumphant and yet tragically riddled with many failed possibilities.