In "Gone Girl," Nick Dunne finds his wife, Amy, missing from their ransacked home. When Nick finds cryptic notes Amy has left, apparently as a part of a game they play each year on their anniversary, the mystery deepens. Meanwhile, a detective becomes suspicious of Nick.
As the movie progresses, the viewer sees flashbacks to how Nick and Amy met, including showing Amy's anniversary game of leaving a series of notes that eventually lead to Nick's gift. In the present day, the search is on for Amy, and Nick is making television appearances. Amy's disappearance becomes big news, and people begin to scrutinize Nick's behavior.
Other flashbacks show that Amy and Nick have both lost their jobs and that they have been having trouble in their marriage. An argument escalates to the point that Nick throws Amy against the stairs. The audience also discovers that Nick has a mistress.
Later in the movie, the audience begins to discover that not everything is as it seems with Amy, either, with a series of surprising revelations as the plot unfolds.
The movie, starring Ben Affleck and Rosamund Pike, is an adaptation of the Gillian Flynn novel of the same name. There are minor differences in the plot in the two versions, but the movie mostly stays true to the book.