Ripley’s shuttle has docked with the Marion. She arrives traumatised, only to find her rescuers under attack by a familiar foe. To make matters worse, it seems that Ash, an android she’d thought killed aboard the Nostromo, has uploaded his AI routines into her shuttle’s computer.

Outside, the ship’s orbit is decaying faster than expected. The crew has just days to escape before they burn up in LV-178’s atmosphere.