The story takes place in the year 2202 , 23 years after the original Alien film trilogy . You play as a Colonial Marine stationed on the UAS Endeavor , responding to a distress call from the Katanga refinery station orbiting the planet LV-895 . Main Campaign Narrative

Released after the main game, this expansion continues the story as the Endeavor crew explores a new, unexplored Engineer ruin ravaged by a deadly infection. It introduces enemies and a hive unlike anything previously seen.

: Your fireteam boards the Katanga station and rescues Dr. Timothy Hoenikker , a Weyland-Yutani scientist who reveals that the corporation discovered Xenomorph eggs and a mutagenic "Pathogen" on the planet below.

: The team discovers an ancient Engineer ship filled with Pathogen. A synthetic intelligence tries to relaunch the ship to Earth, forcing the marines to shut it down to prevent a galactic outbreak.

: The marines descend to LV-895 to investigate Weyland-Yutani ruins and locate another survivor, Cynthia Rodriguez . They discover that the corporation has been experimenting with the Pathogen to create mutated Xenomorphs.