Samantha Caine (Geena Davis) can't remember anything before the day she woke up eight years ago, injured and two months pregnant. Now a schoolteacher with only vague memories of the past, she starts to exhibit bizarre, violent impulses. It's only after hiring two-bit private detective Mitch Hennessey (Samuel L. Jackson) that she discovers that she was once a top CIA assassin named Charley -- and that her old boss has kept tabs on her.