The film Gone Girl concerns the disappearance of Amy Elliot Dunne from her marital home in Missouri. On their fifth wedding anniversary, Amy's husband Nick reports that she has gone missing. Under pressure from the police and a growing media frenzy, Nick's portrait of a blissful union begins to crumble and his behaviour soon has people wondering if he could have killed his wife.

Gone Girl is closely based on the Gillian Flynn's bestselling 2012 book of the same name. One of the film's eventual executive producers, Leslie Dixon, had read the novel in manuscript form in late 2011 and the film version was optioned by 20th Century Fox as soon as the novel was released in June 2012. Flynn negotiated that she would be responsible for the first draft of the screenplay and was already working on it during October 2012 while undertaking an international book tour for the novel.

Although typically authors are removed from the process after the first draft, Flynn remained on board as screenwriter after David Fincher joined as director. With Ben Affleck and Rosamund Pike cast as Nick and Amy, principal photography began in September 2013. The film opened the New York Film Festival on September 25 2014, with the release apparently so shrouded in secrecy that even the lead actors hadn't seen it.

A couple of trailers for the film had been submitted to the BBFC for classification earlier in 2014 and had been passed at the 12A requested by the distributor, 20th Century Fox. The trailers contained the suggestion of a darker edge to the couple's relationship, with shots of the pair arguing, Nick bashing his fist down on a table and a female police officer holding up a pair of red panties on the end of a pen. Towards the end of the trailer, Nick says 'I didn't murder my wife' and the final shot is of Amy's pale face under water, with her eyes open and her hair billowing. BBFC Compliance staff classifying the film noted that there was a dark tone, but no shocking or gory images in the trailer, and so recommended that it could pass at 12A.

The distributor sought advice from the BBFC, stating that they would like to release the feature film at the 15 category. In August 2014, they invited BBFC Compliance Managers to view an unfinished version of the film. This is an example of the BBFC's Advice Viewing service. The print had credits and green screen effects still to be added and an incomplete sound mix. However, key scenes were complete and the Compliance Managers were able to advise on the likely category.

The Compliance Managers agreed that, for the most part, this would be a 15, for over fifty uses of strong language, some strong sex, strong visual and verbal sex references, and visual and verbal references to sexual violence and abuse. However, they felt that a scene of strong and bloody violence during sex raised the film firmly into the 18 category.

The scene in question – when Amy lures her admirer Desi Collings into rough but consensual sex and then cuts his throat during the act – is extremely bloody, with some focus on the wound to his neck, as well as on the blood spraying all over both their bodies. In addition to the significant dwelling on blood and injury, and the callous and sadistic nature of the attack, the 'sexualised' context meant the scene was unprecedented and inappropriate at the requested 15.

Compliance Managers agreed that an 18 category was further reinforced by the late appearance - in quick succession - of four uses of very strong language ('c**t') in one scene. The first, used by Nick to Amy, is aggressive and accompanied by both violence and threat. This is followed by three more uses of the term as she spits them back at him. BBFC language guidance in the Classification Guidelines states that '…aggressive uses of 'c**t' coupled with aggravating factors (including, but not limited to, violence or racial abuse), or four or more uses of 'c**t'' are unlikely to be acceptable at 15.

20th Century Fox were advised that, should they wish to alter the film for a 15 certificate they would have to remove the majority of the throat-cutting scene as well as removing all the uses of very strong language.

The distributor submitted Gone Girl for formal classification on 25 September 2014, with its UK release scheduled for 02 October. It had an 18 request and was passed at that category, with the BBFCinsight: strong bloody violence, very strong language.

The detailed BBFCinsight notes that:

'There is a scene of strong violence, which features a significant focus on blood and injury detail. There is also a scene of domestic violence, and references to sexual violence and abuse.

Over 50 uses of strong language ('f**k), as well as four uses of very strong language ('c**t') in quick succession, accompanied by some violence.

The film also contains several strong sex scenes, strong visual and verbal sex references, and breast nudity.

The film opened in the UK, as scheduled, on 02 October 2014, in top place, with a £4.3 million opening weekend. This made it David Fincher's most successful opening; the 18 certificate did not appear to have affected audience numbers. The film went on to take over $369 million at the international box office.

Gone Girl was critically well-received, garnering several high-profile awards nominations. Rosamund Pike's performance as Amy was particularly praised, and she received Best Actress nominations for a 2015 Academy Award and a BAFTA, amongst others. There were also several nods for Fincher's direction and Flynn's screenplay.

The BBFC received no complaints about the film's rating.