In an alternate-history Soviet Union, mutated parasites capable of taking over human bodies have spread in the wake of the Chernobyl disaster. You are an officer at a special prison where anyone suspected of infection is detained. By day, separate humans from doppelgangers. By night, face the consequences of those you failed to identify.

PRISONER OR DOPPELGANGER?

Bring new arrivals in one at a time, inspect their bodies and clothing, and record any symptoms in their case files. Every prisoner has a charge, a story, and an excuse—but not everyone can be trusted.

UNCOVER WHAT THE EYE CAN’T SEE

A visual inspection isn’t enough. Use a UV flashlight, fingerprint kit, Geiger counter, and other tools to uncover what a doppelganger is trying to hide.

DELIVER YOUR VERDICT

Send healthy prisoners to the general population, suspicious cases to temporary holding, and confirmed doppelgangers for elimination. Keep uncertain cases under observation for up to three days: infected prisoners develop new symptoms, while symptoms in healthy people gradually disappear.

YOUR MISTAKES WAKE UP AT NIGHT

A doppelganger you let through may transform into a monster inside the cell block, while an escaped parasite can hide in the ventilation shafts. When the alarm sounds at night, grab a weapon and stop the monster before it kills every prisoner.

KEEP THE PRISON UNDER CONTROL

Order supplies, feed the prisoners, and monitor the security cameras. Neglect the cleaning, and the prisoners may fall ill.