2122.

A shuttle escapes from the colonial ship Borrowdale. The shuttle carries four survivors—Ward, Albrecht (a Weyland-Yutani employee), Nass, and Mills. Moments later, the Borrowdale bursts apart and explodes. Ward, the shuttle's pilot, responds to the injured members of the crew. Mills remains comatose and unresponsive on a medical cart, but Nass wakes up in a panic.

Ward tries to calm him down by asking whether he remembers what occurred on board the Borrowdale. Nass, who was knocked unconscious during the incident, only remembers waking up on the escape deck. He does make scary references to creatures he saw on board. Albrecht informs them that there was an outbreak aboard the ship, contaminating one or more of them.

Ward orders Albrecht to examine Mills, who is comatose, for contamination. As she works, an enraged Nass accuses her team of the death of their ship and crew. Albrecht admits that her staff destroyed the Borrowdale to stop the virus from spreading.

Nass, certain of Mills' contamination, pulls out his knife with the intention of killing him. Ward tries to ease the situation, but Nass takes her by the throat and tells her that she wouldn't be trying to stop him if she had seen what he saw. He tosses her aside and approaches Mills. He then collapses to the floor, convulsing violently and coughing up blood, revealing his contamination.

Ward rushes to his rescue. When she asks Albrecht for help, the science officer walks out of the chamber and closes the hatch. As the Chestburster tears its way out of Nass, the rest stand by and watch. Ward begs Albrecht to open the door. She refuses, wanting to keep the Chestburster restrained. Yet, a collision with the shuttle's outer hull forces her to trip and release the hatch by accident. Ward overhears a radio transmission that explains the unexpected jolt. Another ship discovered them and is escorting them in for docking.

Ward climbs across to the door and flees into the corridor, as the Chestburster scurries around beneath the cabin's chairs. Albrecht, still lying on the floor, obstructs the hatch from closing. The Chestburster attacks Albrecht, mauling her.

Ward finds herself with nowhere to go after she reaches the shuttle's outside hatch. She sees the rescue vehicle retrieving the shuttle. She scrawls "DO NOT OPEN" on the glass in blood, glancing back at the Chestburster tearing through Albrecht.

Following that, the comatose Mills awakens aboard the shuttle, only to find Nass' body alongside him. He clutches his oxygen mask to his face, reclines on the gurney, and closes his eyes, terrified.