Mystery Fiction Books are a genre of literature that primarily focuses on the investigation of a crime, often a murder, by a protagonist who may be a professional detective or an amateur sleuth. This category often integrates elements of suspense, tension, and intrigue, keeping the readers guessing until the final revelation. While it predominantly belongs to the broader fiction books category, elements of real-life individuals or events may be incorporated, drawing parallels with biography books. The act of reading and collecting such books could be considered a hobby by many enthusiasts.