Step 4: The Reveal
Every mystery story can be boiled down to the following four steps.
1. A Puzzle Appears
2. A Curious Sleuth begins their quest
3. Sleuth discovers Clues and Setbacks
4. Sleuth reveals the Truth
A mystery is a story that opens with a question (step 1). In this, the last step, we need to answer that question.
There are several strategies for revealing the answer.

The Classic Gathering
The sleuth assembles all the suspects in one location where she dramatically explains the entire crime and the reveals the culprit.
Examples: Clue, Knives Out

The Chase
Some stories end with a climactic chase to capture the criminal. Sometimes, they’re identified but flee.
Examples: Murder Mystery, Scooby Doo cartoons

Final Confrontation
Some mysteries end in a dramatic confrontation, often a final showdown between sleuth and criminal.
Example: Seven

The Twist
Subvert the reader’s expectations with a surprise, where someone completely unexpected is the culprit. Sometimes an innocent person is framed; sometimes a murderer gets away with the perfect crime.
Examples: Psycho, The Usual Suspects

The Confession
The criminal is cornered and captured. There’s no escape and they confess. Many TV cop shows end with a confession, once the suspect is confronted with a mountain of evidence.

Open Ended
Some stories provide an ambiguous ending that encourages readers to arrive at their own conclusions.
Examples: Total Recall, In the Woods
Note that not answering the central question in the mystery risks frustrating readers.