I’m slowly getting a grasp on (some) types of mystery plots.  Here’s my first one, which I’m going to call The Mistake.

  1. A crime occurs.
  2. There are three suspects.
  3. The criminal is not one of those three suspects.
  4. The solver rotates through investigating the three suspects, and may even form a valid-sounding theory about one of the three suspects as the criminal.
  5. Then something knocks everything over for the solver and they realized they were wrong all along, and the criminal was this other person.
  6. Big reveal, wrapup, the end.

I’ve been doing this one mostly in ghostwritten cozies, so I can’t direct you toward any that I’ve written.  Yet.  You’ll see this one mostly in cozies (although it certainly isn’t the only possible cozy plot!); it’s good for distracting the reader without leaving an area.  Agatha Christie likes to make the criminal one of the initial suspects, “prove” that they couldn’t have done it somehow, then actually prove later that they did.