Private investigator Tom Welles is contacted by Daniel Longdale, attorney for wealthy widow Mrs. Christian, whose husband has recently died. While clearing out her late husband's safe, she and Mr. Longdale find an 8mm movie which appears to depict a real murder, but Mrs. Christian wants to know for certain.
After looking through missing persons files, Welles discovers the girl is Mary Ann Mathews, and visits her mother, Janet Mathews. While searching the house with her permission, he finds Mary Ann's diary, in which she says she went to Hollywood to become a film star. He asks Mrs. Mathews if she wants to know the truth, even if it is the worst. She says that she wants to know what happened to her daughter.
In Hollywood, with the help of an adult video store employee called Max California, Welles delves into the underworld of illegal pornography. Contact with a sleazy talent scout named Eddie Poole leads them to director Dino Velvet, whose violent pornographic films star a masked man known as "Machine." To gain more evidence, Welles pretends to be a client interested in commissioning a hardcore bondage film to be directed by Velvet and starring Machine. Velvet agrees and arranges a meeting in New York City.
At the meeting, attorney Longdale appears and explains that Christian had contracted him to procure a snuff film. Longdale says that he told Velvet that Welles might come looking for them. Realizing that the snuff film was authentic, Welles knows he is at risk. Velvet and Machine produce a bound and beaten California, whom they abducted to force Welles to bring them the only surviving copy of the illegal film. Once he delivers it, they burn it and kill California. As they are about to kill Welles, he tells them that Christian paid $1,000,000 for the film. Velvet, Poole, and Machine received much less and that Longdale kept the major portion. In an ensuing fight, Velvet and Longdale are both killed; Welles wounds Machine and escapes.
He calls Mrs. Christian to tell her his discoveries and recommends going to the police, to which she agrees. Arriving at her estate, Welles is told that Mrs. Christian committed suicide after hearing the news. She left envelopes for the Mathews family and Welles: it contains the rest of his payment and a note reading, "Try to forget us."
Welles decides to seek justice for the murdered girl by killing the remaining people involved. Tracking down Poole, Welles takes him to the shooting location and tries to kill him. He calls Mrs. Mathews to tell her about her daughter and asks for her permission to punish those responsible. With that, he returns and pistol-whips Poole to death, burning his body and pornography from his car. Welles traces Machine and attacks him at home. Welles unmasks him, revealing a bald, bespectacled man named George. He says, "What did you expect? A monster?" George goes on telling Welles that he has no ulterior motive for his sadistic actions; he does them simply because he enjoys it. They struggle, and Welles kills him.
After returning to his family, Welles receives a letter from Mrs. Mathews, thanking him and suggesting he and she were the only ones to care about Mary Ann.Nicolas Cage as Tom Welles
Joaquin Phoenix as Max California
James Gandolfini as Eddie Poole
Peter Stormare as Dino Velvet
Anthony Heald as Daniel Longdale
Myra Carter as Mrs. Christian
Catherine Keener as Amy Welles
Norman Reedus as Warren Anderson
Amy Morton as Janet Mathews
Torsten Voges as Stick
Luis Saguar as Manny
Chris Bauer as George Anthony Higgins / Machine
Jenny Powell as Mary Ann Mathews
8mm opened in 2,730 theaters in North America and made $14,252,888 in its opening weekend with an average of $6,013 per theater ranking number 1 at the box office. The film made $36,663,315 domestically and $59,955,384 internationally for a total of $96,618,699, more than double its $40 million production budget.
The film received negative reviews from critics. It has a rating of 22% on Rotten Tomatoes based on 80 reviews with an average rating of 4.2 out of 10. The consensus was "Its sadistic violence is unappealing and is lacking in suspense and mystery." The film also has a score of 19 out of 100 on Metacritic based on 20 reviews indicating "overwhelming dislike."
Roger Ebert was one of the film's admirers and gave the film three stars out of four, stating on his website "I know some audience members will be appalled by this film, as many were by Seven. It is a very hard R that would doubtless have been NC-17 if it had come from an indie instead of a big studio with clout. But it is a real film. Not a slick exploitation exercise with all the trappings of depravity but none of the consequences. Not a film where moral issues are forgotten in the excitement of an action climax. Yes, the hero is an ordinary man who finds himself able to handle violent situations, but that's not the movie's point. The last two words of the screenplay are "save me" and by the time they're said, we know what they mean."
The film score was composed by Mychael Danna. It was released on CD by Chapter III in 1999, with a total of 20 tracks:
- "The Projector" (1:20)
- "The House" (2:05)
- "The Call" (1:44)
- "The Film" (1:10)
- "Cindy" (0:56)
- "Missing Persons" (4:46)
- "What Would You Choose" (3:11)
- "Hollywood" (2:51)
- "Unsee" (1:20)
- "Dance With the Devil" (5:36)
- "The Third Man" (1:14)
- "Loft" (1:56)
- "No Answer" (1:47)
- "I Know All About..." (1:41)
- "366 Hoyt Ave." (1:46)
- "Scene of the Crime" (5:52)
- "Machine" (3:30)
- "Rainstorm" (3:49)
- "Home" (1:32)
- "Dear Mr. Wells" (1:54)