To the casual observer, Ann Foster leads an idyllic life on a beautiful estate in southeastern Wisconsin. There, Ann and her husband, Brad, have known great happiness, as they've seen their two children, Andy and Jenny, grow. Jenny and her father are inseparable, and now her son is off to college. Life should be perfect ... but Ann starts experiencing strange premonitions of danger. Concerned, her husband suggests that she seek medical attention, but the doctor assures them that everything is fine. Ann lands a job at an advertising agency, and Mark Manchester is her boss. But when Ann survives a brutal home invasion and other frightening events, it looks like her premonitions were actually predictions of danger. Mark reaches out to his employee, and Ann finds his compassion and support to be a great comfort in scary times. When she sees him talking to two men she feels are stalking her, however, she starts to worry that maybe Mark isn't what he seems. Complicating matters more, while on a business luncheon with her boss, she is surprised to see her husband out with his client, Suzette Monnet. These events only fuel her paranoia and suspicion, and Ann fears that she can't trust anyone. Just when she thinks things can't get any worse-they do. Alone at home one night, she's attacked, and in her last moment of consciousness, looks up to see Jenny's rifle aiming down from above. At that moment, Ann knows that their lives will never be the same.