Librivox: Red House Mystery, The by Milne, A. A.

Summary: Antony Gillingham arrives at the Red House moments after a gunshot is heard. The room is locked, the murderer has disappeared and, in Antony's opinion, the police are going about it the wrong way. Antony, who was looking for a new profession anyway, decides to solve the murder himself, with a little help from his friend Bill. (Summary by Kristin Hughes)