Suddenly the vessel piloted by Colin Barrow crashes into the hangar just as he cuts communication and is killed by his mutated wife. On board the Ishimura, Alissa Vincent, head of the security on the ship, demands that Captain Mathius allows an investigation of the recent outbreak of violence, but Mathius remains firm in the belief that nothing is amiss. As Colin flees the facility with the body of his dead wife, he is unaware of an alien presence flying into the closing shuttle door and attaching itself to his deceased wife.

In his wife Jennifer's room, Colin finds symbols of the Marker written all over the walls and watches in shock as Jennifer cuts into her throat with a Rock Saw shortly after muttering how 'they want our bodies'. Shortly after landing their shuttle, the men discover that something is amiss and Colin goes out in search of his wife, Jennifer, while Glenn eerily vanishes during a quick blackout. When the Ishimura brings up a chunk of the planet for mining purposes, the colony's power goes out and two miners, Colin Barrow and Glenn, set down after a fly-over and begin to investigate a seemingly deserted part of the colony. Hostilities begin to break out as members of the religious group, the Unitologists, beg for a glimpse of the Marker, a key icon in their religion. A week passes and a rash of violent attacks between the miners and other crew begin to rise in numbers. They discover an object referred to as a ' Marker' on the planet's surface the artifact is later brought aboard the Ishimura by orders of Captain Mathius. One of them notes chemical weathering on the walls and another takes note of what appears to be a claw mark. Going back in time, three patrolling inspectors in RIGs move to inspect unusual seismic activity on the planet surface. A screen crackles to life as an exhausted Alissa Vincent gets in the chair in front of the recording device, explaining the fall of the Ishimura due to an infestation of parasitic alien-organisms brought about by an artifact discovered on the surface of Aegis VII and tells the recipient of the message that the Ishimura and the artifact must be destroyed.

Dead space downfall and aftermath