A "Locked Room Mystery" is a subgenre of detective fiction where a crime, typically a murder, occurs in a seemingly impossible situation. The crime takes place in a sealed environment, such as a locked room, where no apparent means of entry or exit exists for the perpetrator. This setup challenges detectives and readers to solve the puzzle of how the crime was committed. These mysteries often feature clever plots and intricate details, requiring the detective, often an amateur or professional sleuth like Hercule Poirot or Sherlock Holmes, to uncover hidden clues. The resolution usually involves revealing a surprising twist that explains the impossible circumstances surrounding the crime.