Susan Harris is home alone when suddenly all the windows and doors are locked and the phone stops working. Susan is trapped by an intruder... but he is not a usual criminal, but a computer named Proteus, who has learned to think logically with his artificial intelligence. And he knows how to spread panic.

In this rousing techno-thriller based on the novel by Dean Koontz, Julie Christie shows "one of her best and most sensitive performances" (Danny Peary, Guide for the Film Fanatic). The Devil's Seed is exciting, full of surprises and peppered with special effects. Susan desperately tries to understand her kidnapper's way of thinking and trick him. Until she finally learns what Proteus is up to: He wants to father a child that she is supposed to carry so that it can rule the world.