Single White Female

Everything in New York based software designer Allison Jones' life is on the upswing, she outwardly "put together". She lives in a spacious albeit slightly run down character apartment with her loving fiancé Sam Rosten. Her best friend, gay actor Graham Knox, is just a stone's throw away in another apartment upstairs if she ever needs him. And her own company is getting off the ground with her first major client, Mitchell Myerson, who, despite negotiating her fee down, she knows will provide her further contacts to expand her business. Her life takes a turn when she discovers that Sam was unfaithful in having what sounds like a one-time only, unplanned sexual encounter with his ex-wife, Allie ending their relationship as a result. So she advertises for a female roommate to fill the void left by Sam to occupy the spare bedroom. Allie ends up choosing a last minute applicant, Hedra Carlson, as an act by her during her interview demonstrated that she could become a true friend. While their roommate situation starts out positively for both of them, Allie begins to notice unusual behavior by Hedy, including she doing whatever she believes protects Allie, and she trying to mimic her in small ways, which may have something to do with Hedy's twin sister being stillborn, something she divulged in her interview. The situation gets worse when first Allie and Sam reconcile potentially leaving Hedy out in the cold, and second Allie has an unwanted encounter with Mitchell. Allie is initially unaware of just how this unusual behavior could manifest itself as a true danger to her.

In New York, the PRs colleagues and roommates Holly Parker and Jan Lambert are disputing a promotion in their agency. The unethical Jan deceives Holly and sends her to Chicago; meanwhile, she seduces Holly's boyfriend David Kray, in the opening of the fancy restaurant of his own, and they have one night stand. When Holly arrives back home, she finds that David cheated her with Jan, and she decides to move to a new apartment. She schedules a visit with the needy Tess Kositch, and they become roommates and friends. When Tess cuts and dyes her hair identical to Holly's style, she sees that her new roommate is obsessed on her. When Holly follows Tess to the underground night-club "Sin", she realizes that the girl is deranged. But Tess wants to be her friend and put Holly out misery, eliminating her former bad friends.