Dead Space: Downfall

The mining colony on Aegis VII uncovers a monolith-like artifact later identified as the Marker. Unitologists treat it as sacred, but the artifact begins to exert a deadly influence on the colonists. This discovery seeds the chain of events that lead to the outbreak and the Marker’s transfer to the Ishimura.

The Marker is brought onto the Ishimura under Captain Mathius and Dr. Kyne's authority. Unitologist crew members increasingly worship it, while security officer Vincent grows furious about its presence. The tension foreshadows the catastrophic influence of the artifact on the ship.

After the planetcrack begins, contact with the Aegis VII colony is lost and chaos erupts on the surface. Necromorphs overrun the colony as violence and psychosis spread among the miners. The Marker’s influence is implied to drive the breakdown.

Barrows kills herself, and her husband escapes to the Ishimura with her body. They are infected by a stowaway Necromorph and arrive aboard the ship, signaling a new, onboard outbreak looming over the crew. The threat from within begins to take hold.

Chief Alissa Vincent leads a six-person team to investigate a disturbance. They encounter growing numbers of Necromorphs and suffer casualties, with Hanson saved only by Irons’s intervention. The crew’s morale deteriorates as the infection spreads through the ship.

Captain Mathius becomes increasingly paranoid and delusional, prompting the crew to restrain him. Kyne attempts to sedate him, a move that ends with Mathius’s death. The crew scrambles to secure the ship as escape pods are launched.

En route toward the bridge, Hanson descends into madness and kills Shen. Ramirez shoots Hanson to stop the threat and preserve the remaining survivors. The outbreak intensifies as the ship sinks further into chaos.

Samuel Irons sacrifices himself to hold off the approaching Necromorphs, buying time for the others to escape. His death marks a turning point, giving the survivors a fighting chance to continue toward the Marker. The ship’s defenses begin to fail as the infestation accelerates.

Vincent and Ramirez race toward the engines to stop Kyne from crashing Ishimura into Aegis VII. Ramirez dies during the pursuit, and Kyne reveals the Marker's influence over the crew. The ship’s crew realizes the extent of the artifact’s manipulation.

With the panic subsiding, Kyne escapes and the Marker's influence becomes clearer. The Ishimura remains in a decaying orbit, but the Necromorph threat is temporarily contained. The Marker’s power appears to restrict the undead from approaching the artifact.

Vincent reaches the Marker and the Necromorphs cannot approach it, as the Marker keeps them sealed on Aegis VII. She grows tired and begins to hallucinate while confronting the alien object. The artifact seems to immunize the ship’s crew from the infection’s reach.

Exhausted and hallucinating, Vincent records a final video message from the shuttle bay. She opens the bay doors and triggers a distress beacon, drawing the Kellion toward the downed ship. The film ends with the rescue ship answering the distress call, leaving the ending open.