Two hundred years after the death of Ellen Ripley, a group of scientists aboard the spaceship USM Auriga successfully clone her using DNA from blood samples, in order to harvest the alien queen embryos that were inside her when she died. Unaware of her previous life, the cloned Ripley exhibits superhuman traits and a psychic link with the aliens. Meanwhile, a group of mercenaries arrives on the Auriga with several kidnapped humans in stasis to be used as hosts for the aliens, facilitating the scientists' research on the creatures.

As the scientists' experiments with the aliens progress, their activities trigger a catastrophic breach in containment. The creatures escape their confinement and wreak havoc, killing many of the crew. In the ensuing chaos, Ripley, aware of the lethal potential of the aliens, joins forces with the surviving mercenaries, including a mechanically adept woman with her own secrets. Together, they make their way through the infested ship, seeking to escape while dealing with the rapidly growing alien threat. As the group encounters increasingly dangerous situations, they must navigate not only the hostile creatures and the failing ship systems but also the complicated dynamics of their own group.