Locked-Room Mystery Generator
Create an impossible-crime mystery with clear physical constraints, planted clues, and a checkable solution.
Shape your book
Design the actual sequence first, then decide which reasonable assumption makes the event appear impossible.
Worth including
- Describe doors, windows, keys, and observation times consistently.
- Separate what witnesses saw from what they assumed.
- Give the detective a reason to revisit an ordinary detail.
- Let false solutions fail against established evidence.
- Explain the solution step by step using clues already on the page.
Common traps: Adding an unmentioned passage at the reveal; Relying on precise mechanics the draft never establishes.
Try an idea
Common Questions
How does a locked room differ from a closed circle?
A locked-room story centers on an apparently impossible act. A closed-circle story limits who could be responsible, often through isolation. A story may use both, but each creates a different puzzle.
What should I check in the finished draft?
Review the clue order, timeline, and solution. AI can miss instructions; edit the manuscript before sharing or publishing it.
How does the free book work?
Eligible new accounts can create a first book of up to about 10,000 words without a card. Reading and downloading the full book requires unlocking it through trial checkout or a qualifying purchase. A trial renews at the price shown at checkout unless cancelled before renewal.
Can I change the idea before writing?
Yes. Edit the prompt or choose an example, then continue to the book creator to choose your settings. This page carries your idea through signup or login; you review the finished draft before sharing it.