The head-in-the-box ending of “Se7en” was originally rejected by the studio, but David Fincher was accidentally sent the original screenplay with that ending, convincing him to make the movie. The producer still objected to it, but Brad Pitt refused to act in the film unless the scene was kept.
The ending of the screenplay, with the head in the box, was originally part of an earlier draft that New Line had rejected, instead opting for an ending that involved more traditional elements of a detective thriller film with more action-oriented elements. But when New Line sent David Fincher the screenplay to review for his interest in the project, they accidentally sent him the original screenplay with the head-in-the-box ending. At the time, Fincher had not read a script for a year and a half since after the frustrating experience of making Alien 3; he said, “I thought I’d rather die of colon cancer than do another movie”. Fincher eventually agreed to direct Seven because he was drawn to the script, which he found to be a “connect-the-dots movie that delivers about inhumanity. It’s psychologically violent. It implies so much, not about why you did but how you did it”. He found it more a “meditation on evil” rather than a “police procedural”.
When New Line realized that they had sent Fincher the wrong draft, the President of Production, Michael De Luca, met with Fincher and noted that there was internal pressure to retain the revised version; De Luca stated that if Fincher promised to produce the movie, they would be able to stay with the head-in-a-box ending. Despite this, producer Kopelson refused to allow the film to include the head-in-a-box scene. Actor Pitt joined Fincher in arguing for keeping this original scene, noting that his previous film Legends of the Fall had its emotional ending cut after negative feedback from test audiences, and refusing to do Seven unless the head-in-the-box scene remained.