CZ012 · SPOILER-FREE CASE GUIDE

THE FOURTH KEY

A sealed archive, three registered override keys and fresh marks from a fourth turn a document review into a locked-room records mystery.

The Fourth Key is a dense Kuala Lumpur archive case built around physical keys, climate-control logs, document custody and legal records. The setting is quiet and procedural, which makes every unexplained access event matter.

The premise

Dr. Farah Idris is found dead between the compact archive shelves shortly after a climate-control alarm seals Archive 9. Three mechanical override keys are officially registered, yet the lock carries fresh marks from a fourth. Farah had spent the evening digitising a sealed land-compensation file that several people wanted left buried.

What the player is trying to establish

Reconstruct the mechanical-access timeline, identify the unregistered fourth key, and prove who killed Farah to stop the original settlement record from surviving digitisation.

Players must distinguish digital access from mechanical access and connect a missing settlement record to physical traces from an unregistered duplicate key.

Investigation skills this case rewards

Spoiler-free investigation notes

Ready to investigate?

The playable case uses a fixed solution, cloud-saved progress and a ten-minute attempt window. You will need an account so the investigation state can be saved.

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