A mystery where a crime occurs in a sealed space with no apparent way for the culprit to have entered or escaped.
The locked room mystery presents a seemingly impossible crime: a murder in a room locked from the inside, a theft from an impenetrable vault, a disappearance from a watched space. The puzzle isn't just who did it but how it was physically possible. The solution must be logical, surprising, and satisfying, using the constraints of the sealed space to create a mechanical puzzle worthy of the reader's effort.
Locked room mysteries push the whodunit to its logical extreme. They demand the tightest plotting, the most creative thinking, and the most satisfying reveals. Writing one teaches you to think about physical space, logical constraints, and how to make the impossible feel inevitable once explained.
Considered the greatest locked room mystery ever written, including a legendary chapter where the detective lectures on locked-room methods.
An entire island as the locked room: ten people, no way off, dying one by one.
A country house party as locked room, with the twist that the detective relives the day in different bodies.
Design a locked room scenario. Someone is found dead in a room locked from the inside, with no hidden passages. Before writing any story, design the solution: how did the killer do it and escape? Work backward from the method. The cleverness of the solution determines whether the story works.