Kenneth Winslow is an extremely shy but brilliant technical writer who orders a rubber sex-doll. He develops a relationship with "Nikki," to the point of talking and even arguing with her. Kenneth begins to display bizarre behavior, and starts to feel stalked by Nikki. Their relationship evolves into a love-hate situation, and at one point even beats the doll. At work, Kenneth meets Lisa (Melissa Sagemiller), a temp, with whom he begins to develop a relationship. Kenneth encourages Lisa to resemble Nikki by cutting her hair the way Nikki has it and wearing the same clothes Nikki has. As his imagined relationship with Nikki becomes more sinister and dominating, Kenneth resorts to cutting up and disposing of the doll. Lisa eventually becomes aware of Nikki's existence, and promptly breaks up with Kenneth. Later, a bound and gagged Lisa is discovered by Kenneth's landlord, and Kenneth bludgeons him with a hammer. Kenneth then begins to transform Lisa into the doll. He dresses her up in Nikki's clothes, straps her down, and begins to replace her blood with embalming fluid. Lisa manages to escape from her restraints and attacks Kenneth with a small statue, rendering him unconscious. At this point the police arrive, and when they see Lisa over the unconscious Kenneth they shoot her. Lisa, wearing Nikki's clothes, falls dead in the crate Nikki came in, thus completing her transformation. Kenneth is never accused of the crimes. Much later, he re-orders another Nikki. While buying flowers for Nikki, he notices the attractive brunette at the floral shop. The viewer is left to assume the Kenneth's obsessive love triangle cycle will start all over again.