Based on Flynn and Fincher’s decision to have Amy contribute heavily to the first act of the film via voiceover and flashback, it seems they weren’t all that concerned with preserving the novel’s big twist: Amy is not only alive, but has meticulously orchestrated her own disappearance down to the tiniest detail, in an effort to escape her marriage after she learns about Nick’s infidelity. That revelation, telegraphed though it is, becomes a game-changer in the book, but in the film, it serves more as an act break, ushering the story into its next stage without much of a “Gotcha!” moment. And really, that’s okay; Gone Girl is such a hugely popular novel, it would be counterintuitive to sacrifice good storytelling for the sake of a revelation most audience members will probably know going in. By not secreting Amy away in the early going to preserve the twist, the film not only maintains its fidelity to the novel—which intersperses Amy’s diary entries with Nick’s point-of-view chapters—it also makes the depth and breadth of her deceit all the more alarming, and deeply intriguing. 

It would be impossible to make Amy a sympathetic character, but Flynn, Fincher, and Pike achieve the impressive feat of making her madness seem plausible, bordering on understandable. Much of that is on Pike’s delicate shoulders, and she handles it masterfully in her performance, letting tiny hints of Amy’s damaged psyche peek out through her cold, calculating facade. But Flynn’s screenplay, drawing from the novel, helps matters by returning again and again to the specter of “Amazing Amy,” the book series Amy’s parents created to realize a better, more perfect version of their own daughter. The line between Amazing Amy and Actual Amy’s plot to escape her marriage is never explicitly drawn, but her parents (played by Lisa Banes and David Clennon) are very present in the story, a reminder of the performative perfectionism that comprises Amy’s life. When something threatens the sanctity of that performance—in this case, her husband—she creates a new reality, one that she believes she controls. 

As performed by Pike, all big eyes and tense shoulders, Amy takes on the quality of a cornered animal lashing out with instinctual violence. She does horrible, unforgivable things, but she does them out of deeply entrenched self-preservation. That said self-preservation results in a new life, an unwanted child she forces upon Nick—and herself—to preserve the illusion she’s created, is the story’s biggest irony, one bound to leave unsuspecting audiences feeling deeply unsettled. In the hands of Pike, Fincher, and Flynn, Amy becomes one of the most nuanced and compellingly flawed characters to reach multiplex screens in a long time—and like Nick, viewers will find her hard to shake.