A Special Forces team is sent to rescue a reporter, Ángela, from an apartment complex overrun by infected civilians. After completing their mission, Ángela wakes up aboard a quarantined ship, where Dr. Ginard conducts tests on her. Survivors Lucas and Guzman are also on board, and the doctors investigate a pathogen causing the outbreak, linking it to a worm-like parasite.

The crew is infected, and chaos ensues as Ángela and the others struggle to survive. As events unfold, Ángela discovers that the parasite transferred to Guzman, who attempts to infect her.

With the ship’s self-destruct initiated, Nic and Ángela escape, killing Guzman in the process. In the end, they narrowly avoid death as the ship explodes, and a parasite is seen moving inside a fish, implying the horror is not over.