Mystery fiction is a loosely-defined term that is often used as a synonym for detective fiction — in other words a novel or short story in which a detective (either professional or amateur) investigates and solves a crime. The term "mystery fiction" may sometimes be limited to the subset of detective stories in which the emphasis is on the puzzle element and its logical solution (cf. whodunit), as a contrast to hardboiled detective stories, which focus on action and gritty realism. However, in more general usage "mystery" may be used to describe any form of crime fiction, even if there is no mystery to be solved.
See mystery for a list of mystery books on the wiki.