The movie stars Nicolas Cage as an enigmatic family man named Tom Welles who works as a private investigator and comes home to a good marriage with his wife (Catherine Keener) and baby. He specializes in top-level clients and total discretion. He's hired by the lawyer for a rich widow who has found what appears to be a snuff film in a safe belonging to her late husband; she wants reassurance that the girl in the film didn't really die, and Welles tells her snuff films are "basically an urban legend -- makeup, special effects, you know."
The film follows Welles as he identifies the young woman in the film, meets her mother, follows her movements and eventually descends into the world of vicious pornographers for hire, who create films to order for a twisted clientele.