Private detective Tom Welles (Nicolas Cage) lives a normal life with his wife (Catherine Keener) and young daughter, until he receives a startling new case. A widow named Mrs. Christian (Myra Carter) has found what appears to be a snuff film among her late husband's belongings, and she wants Welles to determine if the movie is real or fake. Welles heads to California, where a video store employee (Joaquin Phoenix) helps him infiltrate the dangerous and depraved world of illegal porn movies.