The Mystery of the Yellow Room

Gaston Leroux's The Mystery of the Yellow Room is one of the earliest and most famous locked-room mystery novels. The plot involves an amateur detective (Joseph Rouletabille) who partners with a famous French investigator (Frédéric Larsan) to solve a seemingly impossible case in which a wealthy woman is nearly beaten to death while her attacker is able to escape the room with the door still locked from the inside. The narrative is intricate and detailed, and I especially like the way Leroux includes floorplans and diagrams of the crime scene. The book still has some far-fetched elements — e.g., the fact that the teenage Rouletabille essentially leads the investigation, the over-reliance on some massive coincidences in the course of the investigation, etc. — but this is a well-structured and mostly plausible story.