The Mystery of the Yellow Room (1908) is Gaston Leroux's masterpiece and during his lifetime his most successful book. It is one of the classics of early 20th-century detective fiction. At the heart of the novel is the enigma: how could a murder take place in a locked room, which shows no sign of being entered? The novel is also about the rivalry to solve the case between the detective Frederick Larson, and a young investigative journalist, Rouletabille. Larson finds a suspect who is put on trial, only to have him cleared by Rouletabille, who reveals in the most dramatic fashion the identity of the real murderer.