A mystery is simply an unsolved question and the attempt to answer it. In literature, this mystery is often a crime, but anything unexplainable can inspire a great mystery novel.
Like all genre fiction, Mystery follows a formula, one that readers expect. The thing that must happen: something unexplainable. It could be a crime, a disappearance, or the impossible arrival of something or someone. (Gillian Flynn’s Gone Girl checks several of these boxes.) Once the mystery is declared, an investigation begins. Clues and witnesses are gathered; suspects emerge. At some point, everything will go off the rails thanks to red herrings or last-minute alibis.
Eventually, the investigation takes a giant leap forward — whether it’s a crucial clue or a tortured confession — and, at last, the mystery is solved. But that’s not necessarily the end of the story. If a crime has been committed, the criminal needs to be caught. If someone disappeared, they need to be found. And, of course, all villains should receive the punishment they deserve.
Mysteries are typically told chronologically from the time the mystery is discovered to the instant it’s solved, but not always. Sometimes, the mystery is solved early in the novel, and the rest of the storyline is spent searching for the motive or the criminal, as in Tom Rob Smith’s Child 44. Whatever the timeline, all mystery novels create the same questions for the reader: Who is responsible for the mystery? What are the details of what happened? Why did this happen? If anyone deserves punishment, is justice served?
The suspense genre is closely related to a mystery or thriller, which can make it difficult to classify. Often, the three genres are lumped together by publishers and classified as Mystery/Suspense or Suspense/Thriller, but other times they are kept separate. So how do you know if you’re writing a suspense novel?
In general, “suspense” refers to the sense of worry or anticipation a reader feels when reading. This means, in general, all mysteries and thrillers contain suspense. What differentiates them is the type of suspense that is created throughout your story.