Movie page 13
You're referring to the infamous "Page 13" from the movie "American Psycho" (2000) directed by Mary Harron, based on the novel by Bret Easton Ellis.
Page 13 is a pivotal scene in the film where the protagonist, Patrick Bateman (played by Christian Bale), is shown to be a serial killer who brutally murders and dismembers his victims. The scene is notorious for its graphic content, including the use of fake blood, prosthetics, and special effects.
The scene has been widely discussed and debated among film critics and scholars, with some arguing that it's a commentary on the superficiality and violence of 1980s yuppie culture, while others see it as a gratuitous and disturbing depiction of violence.
Regardless of interpretation, Page 13 has become a cultural reference point and a symbol of the film's controversial and provocative themes.