|“||I can't lie to you about your chances, but... you have my sympathies.||„|
|~ Ash taunts the survivors|
He was portrayed by Ian Holm.
He is the Nostromo's inscrutable science officer. He administers medical treatment, conducts biological research and is responsible for investigating any alien life forms the crew may encounter. It is at Ash's insistence that the crew investigates the mysterious signal emanating from LV-426. Ripley becomes suspicious of him when he breaks quarantine protocol by allowing Kane, Dallas, and Lambert to re-enter the Nostromo while the Alien facehugger is attached to Kane. Captain Dallas later informs Ripley that Ash had abruptly replaced the ship's previous science officer, whom Dallas had done six previous missions with, just as the Nostromo left Thedus for its return journey to Earth. Over Ripley's objections, Dallas entrusts Ash with all science-related decisions.
After the Alien has killed Kane, Brett and Dallas and went on its killing spree across the ship itself, Ripley had 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 attacks her. He is hit in the head by Parker, and the force almost completely severs his head. It is at this point that Ash is revealed to be a synthoid. After suggesting that the crew will not survive the Alien's attacks and giving them his sympathies, Ash is deactivatd by Ripley and destroyed by Parker using a flamethrower.
As an advanced synthetic, Ash could effectively mimic human emotions and mannerisms to the degree that his crew mates were deceived into believing he was in fact human. Outwardly, Ash was calm, collected and intelligent, and seemingly considered himself superior to the rest of the crew, particularly Parker and Brett, which means that he is also an egotist. With regards to his secret orders, Ash clearly had no qualms with sacrificing the crew to ensure the Alien was returned to Earth. On several occasions he directly assisted in the creature's progress and survival, although always subtly enough that his actions would not appear to be an outright betrayal of the rest of the crew. Similarly, he would often appear to assist in the fight against the Alien, most notably when he constructed motion detectors following Kane's death, although in hindsight it is clear his assistance was always specifically limited in its effectiveness. Despite his care, Ripley became suspicious as soon as Ash breached quarantine rules by allowing Kane and the Facehugger back on board the Nostromo, something a Science Officer — in Ripley's mind at least — would never do. When discovered, Ash displayed a cruel and sarcastic side, taunting the other survivors and mocking their futile attempts to kill the Alien.
Ash was also an adept liar, successfully concealing from the rest of the crew the fact that Weyland-Yutani had already deciphered much of the transmission coming from the derelict before they had even left Thedus. He feigned ignorance when the signal was assumed by the others to be a distress call, even though the company had already learned enough from the message to know that the Xenomorph the Nostromo had surreptitiously being sent to retrieve was an incredibly dangerous creature likely to kill the entire crew.
Although first and foremost an entity programmed to execute its mission with ruthless pragmatism, Ash's consciousness relates in the diary he kept aboard the Narcicuss' computers that he genuinely respects Ripley; admiring his enemy's bravery, strength, resourcefulness and tenacity, much like how he admired the Drone aboard the Nostromo for similar reasons. Poignantly, he also longs to converse with her, as his program has grown to be able to feel loneliness in his 30 years of solitude as Ripley slept.
- Ash is the first villainous android in the franchise. The second being David 8, the Bigger Bad of the entire Alien saga.