Double Indemnity is a 1944 film noir directed by Billy Wilder. The film is known for setting the standard for its genre (some argue it being one of the first) and putting Wilder's name on the map as an innovative director. The film's influence is firmly cemented and continues to this day.
Wilder was known for his tendency to remove vital scenes from final prints of his films. Double Indemnity had two different scripted endings: one of which was filmed, another which never made it past the scripting phase. The ending that was never filmed was the one written in the novel. The two main characters, Walter Neff and Phyllis, overcome with guilt commit double suicide. The ending, naturally, would have conflicted with the Hayes Code and was probably never intended to be filmed.
The second ending was filmed and was intended to be in the film. The ending involved Neff being executed in a gas chamber with an associate of his, Keyes, looking on in the distance. It was shown to test audiences and was received well, but Wilder decided the ending was unnecessary and ended the film in Neff's office, with a final monologue from him to Keyes. A Hayes Code associate deemed the original ending "unduly gruesome".
This ending hasn't been seen since it was screened to test audiences shortly before the film's release. The footage has been lost completely, apparently mishandled by Wilder's estate. A few production stills survive, along with a few different versions of the script. It is one of the most sought-after missing alternate endings in film.