Ash was a Hyperdyne Systems model 120-A/2 synthetic that was created for Weyland-Yutani in the early part of the 22nd century. Ash was later switched in to the Nostromo's roster by the company to oversee a specific retrieval mission, thereby replacing another science officer from that roster two days before the Nostromo departed from Thedus.
The Nostromo Incident
In 2122, the Nostromo's onboard computer, "MU-TH-UR" (Mother) intercepted a distress beacon originating from the planetoid LV-426 within close proximity to the ship. The crew members are awakened prematurely from their hypersleep. Ash was able to convince the crew to investigate the mysterious signal emanating from LV-426 by using Weyland-Yutani's company protocol as an excuse. Ripley became suspicious of him when he broke quarantine protocol by allowing Kane, Dallas, and Lambert to re-enter the Nostromo while the facehugger was attached to Kane.
Ash and Captain Dallas attempted to pull the facehugger from Kane's face, but the creature tightened its grip around his neck. Ash later tried with a laser scalpel to remove one of the "digits" of the creature, but this caused it to bleed acid that ate through several floors in the ship. He later called Dallas down to the infirmary to inform him that the creature released itself from Kane's face. Dallas, along with Ripley and Ash looked for the creature around the infirmary and the creature landed on Ripley dead. Ash later dissected the creature and was interrupted by Ripley and was growing annoyed by her questions.
Ash later notified Captain Dallas that Kane's condition changed and that he was now conscious. After Kane was visited by the crew, Dallas told the crew that he would get the last meal before going back to hypersleep. Ash joined the crew for the last meal and was present when Kane went into convulsions and helped restrain him. As Ash and the others restrained Kane, a creature ripped out of his chest killing him. As Parker was going to kill the creature, Ash talked Parker out of killing it. Before the crew could catch it, the creature escaped into the ship.
After the crew came up with a plan to catch the creature, Ash developed a motion tracker to find it easier. The crew split up in to two teams with Ash being with Dallas and Lambert. Ash later heard that the creature grew to at least the size of a man and that it attacked Brett and took him into the vents.
Ash was later paired up with Ripley when Dallas volunteered to go into the ducts to flush the creature out and blow it out the airlock. As Dallas made his way through the ducts, a signal came up on the tracker and Lambert yelled at Dallas to get out of there as the signal was moving towards him. Unfortunately, the creature got Dallas in the airducts and all Parker found was his incinerator.
After the Alien killed Dallas, Ripley discovered through the ship's computer "MOTHER" that Ash has been given special orders by the Weyland-Yutani Corporation to ensure the return of the Alien to the company's laboratories, even at the expense of the crew. When confronted by Ripley, Ash attacked her. He was hit in the head by Parker, and the force almost completely severed his head. It was at this point that Ash was revealed to be an android. After suggesting that the crew would not survive the Alien's attacks and giving them his sympathies, Ash was destroyed by Parker using a flamethrower.
Due to his betrayal of the crew, Ripley harbored a deep distrust and hatred for androids that would stay with her decades later. She would later take the hatred she had for Ash out on another synthetic: Bishop. Ash's situation was not unique; as other ships reported androids that were known to explode like Ash did on the Nostromo. By 2179 synthoids were now equipped with inhibitors to keep from "malfunctioning", harming humans or doing anything that would endanger a human's life. Ash's picture was displayed during a debriefing about the Nostromo on Gateway Station on the fate of the ship and her crew. The events on the Nostromo also left a distrust towards the Weyland-Yutani Company for putting the lives of others aside to study and harness the potential the xenomorphs had. This also shaped Ripley's decison making skills during her future encounters with the creatures.
- Dan O'Bannon's original script treatment for Alien did not include Ash. Producers Walter Hill and Ronald Shusett felt that the film needed a secondary story element, so they added the sub-plot of Ash, the android spy who ultimately betrays the crew. O'Bannon was displeased with this, feeling that it was a cheap gag and disingenuous to his original vision. He referred to the new material as suffering from "Russian Spy" syndrome.
- On the director's commentary for the Alien special edition DVD, Ridley Scott attempts to ratonalize the scene where Ash tries to kill Ripley. Scott ascribes a Freudian sexual conflict to the character of Ash, noting that as an android, Ash is not anatomically correct, and vents his sexual frustration upon Ripley when he forces her to fellate a rolled-up pornographic magazine.
- Like all the synthetics that appeared in the films, Ash follows an alphabetical name pattern with regard to the film release dates: Ash, Bishop, Call, David.
- Ash's blood is colored water. Milk was not used as it would have gotten very smelly very quickly under the hot studio lights. Milk was used though for the close-up of his innards, along with pasta and glass marbles.
- According to Ian Holm, Ash's head contained spaghetti, cheap caviar and onion rings.
- Actor Ian Holm, who plays Ash in Alien, is the same actor who plays Bilbo Baggins in The Lord of the Rings and The Hobbit film series.