In the climactic scene of Se7en, villain John Doe (Kevin Spacey) delivers a box to rookie detective David Mills (Brad Pitt) that contains the decapitated head of his wife Tracy (Gwyneth Paltrow) in order to bait Mills into killing him, thus completing his murderous, biblically themed performance piece.
When Pitt read the script, he fell in love with it, but he knew that the producers were going to have major reservations – specifically, with Paltrow’s brutal off-screen death, and Spacey’s villain “winning” in the end. As a condition of agreeing to do the movie, Pitt made the producers promise that the ending would be filmed as written, and that they wouldn’t cop out at the last minute by having Mills arrest Doe, or Paltrow pop out of a cake and yell “psych!” at the end.
But after the first press screenings, producers responded exactly the way that Pitt feared: They went into panic mode and tried to figure out how to reshoot the ending without the Paltrow jack-in-the-box. The alternative ending – the one they seriously almost went with – was that Doe decapitates Mills’ dog instead.