Choose the question that matters
A mystery begins with a gap readers want to close. Why is a suitcase abandoned? Who removed an address? What changed between two photographs? The answer needs a human consequence. Otherwise the reveal may feel like an interesting fact rather than the resolution of a story.
Give the investigating character a reason to care that goes beyond curiosity alone.
Let clues do real work
A fair clue can be noticed before its meaning is understood. Use an object, a repeated phrase or a contradiction that changes as new information arrives. Red herrings should have believable explanations, not exist only to waste time.
Track who knows what and when. If the solution depends on information no reader could have encountered, the final surprise can feel arbitrary.
Resolve more than the puzzle
The answer should change a relationship, a decision or the character’s understanding. A quiet reconciliation can be as satisfying as a dramatic confrontation when it addresses the story’s central question. Before publishing the last chapter, reread the first. Check that the reveal accounts for the important details and that the opening promised the kind of ending you deliver.
