Users in The Callisto Protocol are transported to an alternative year 2230 to the territory of a mysterious prison institution, about which terrible legends are made up in the system. The location of the penal colony is known to all average citizens – the facility is controlled by the commercial structure of the local spill and is located right in the area of ​​Callisto, one of the natural satellites of Jupiter.

At the center of the narrative of The Callisto Protocol is a prison director who takes his official duties seriously. He tries to carefully control the prisoners and his employees. During an unscheduled inspection, a terrible truth is revealed to the protagonist – one employee is involved in a freelance invasion of the perimeter. The picture of what is happening is simply terrifying – an unknown extraterrestrial creature mocks and tears the poor criminal into pieces. Chaos begins in the institution, because enough of these mutants have been launched to capture the facility.

The central character gathers all his strength into a fist to find the culprit of the emergency and beat out of him the truth of what is actually being prepared by the aliens. Making his way through corridors and rooms, the daredevil fights evil spirits with the help of firearms with limited ammunition. Protective armored equipment with modifications will help protect you from enemy attacks. When moving, it is worth considering not only the power of the opposing side, but also the conditions of the surrounding space.