When the synthetics industry began faltering in the 24th century, a new second generation was released: the Autons, a line of machines made by machines. This endeavor backfired however when the Autons began rebelling against their human masters, resulting in a bloody rebellion known as "The Recall." During this rebellion, Autons burned out their modems to cut live connections to any United Systems' systems, which could have been used to try and guide or reprogram synthetics.
Before burning her modem, Annalee Call managed to access classified military files concerning studies and experiments involving Xenomorphs. Her basic programming principles of not harming or letting harm happen to humans and humanity at large compelled her to put an end to threat to humanity the Xenomorphs presented.
Annalee Call first appeared in Alien Resurrection, the fourth film in the Aliens franchise. She was portrayed by actress Winona Ryder. Due to a traumatic near-drowning at a young age, Ryder suffers from aquaphobia and had some trouble with the underwater scenes of the film, some of which had to be re-shot numerous times.