Although there is no single definition for the genre known as mystery fiction, most agree that the stories are about the solving of a crime, often murder, through an investigation. From a circle of suspects, each with the motive and opportunity to have committed the crime, the detective, whether professional or amateur, solves the mystery by making logical deductions from the facts presented.
The genre emerged about 200 years ago with the development of literacy and the influences of Edgar Allan Poe, Wilkie Collins, and Arthur Conan Doyle. More recently, the genre has diversified into various subgenres including but not limited to the cozy mystery, the police procedural, and the hardboiled PI.
Cozy mysteries are so named because they take place in a confined setting, such as a village or estate. Moreover, there is no explicit sex or violence. Agatha Christie, though not the first, is the queen of cozies. Her most acclaimed books are And Then There Were None, Murder on the Orient Express, and The Murder of Roger Ackroyd.
Ed McBain (a.k.a. Evan Hunter) popularized the police procedural with his 87th precinct novels set in a fictionalized New York City. Instead of focusing on a single cop, each novel features some subset of the detectives in the precinct. Accordingly, McBain influenced the creation of such TV police procedurals as Hill Street Blues and NYPD Blue.
Hardboiled PI mysteries are those showcasing a private investigator working alone for justice in a corrupt, sometimes harsh world. My favorites are Lawrence Block’s Matthew Scudder stories, Robert B. Parker’s Spenser novels, Walter Mosley’s Easy Rawlins books, and Sue Grafton’s alphabet series. But don’t forget the forerunners who shaped this subgenre: Dashiell Hammett, Raymond Chandler, and Ross Macdonald. Other subgenres include suspense, espionage/spy, paranormal, legal or medical thrillers, and noir.
But all of these subgenres can be further classified by their setting. For example, Victoria Thompson’s Gaslight series is situated in turn-of-the-century (19th to 20th) New York City. Anne Perry’s Charlotte and Thomas Pitt stories take place in Victorian London. And Ariana Franklin’s and Umberto Eco’s masterpieces are set in the Middle Ages, in Cambridge, England and an Italian abbey respectively.
From here we can sort the stories by the type of mystery. Is it a quest or puzzle? Is the puzzle a locked-room mystery, usually a murder in which it appears impossible for the perpetrator to have gotten in and out of the room? So there’s a mystery subgenre for every taste.
Based on these categories, I would classify the novels in my Miriam bat Isaac series as amateur sleuth historical mysteries set primarily in Roman Egypt, specifically the city of Alexandria, during the first century CE. The first two books, The Deadliest Lie and The Deadliest Hate, are quests. The third, The Deadliest Sport, which is coming next, is a locked-room mystery. The fourth? Uh-uh. I’m not telling yet, but it will be different from the first three.