"The only really stable character in this house is the cat," remarked a reporter at the press conference following the screening of 'Gone Girl' that kicked off the New York Film Festival. But as Tyler Perry said, "You haven't met the cat."

"The cat was really hard to get. He was really hard to cast, he was very difficult on set," said Gillian Flynn, author of the original novel and writer of the film's screenplay, before Ben Affleck joked, "He’s a half-dead cat."

For as funny as this exchange was, it is, nonetheless, quite true -- the cat is the only sane one in this movie.

'Gone Girl' is David Fincher's highly anticipated film adaptation of Flynn's best-selling novel, and stars Ben Affleck and Rosamund Pike as Nick and Amy Dunne. On the morning of the couple's fifth wedding anniversary, Amy has gone missing and Nick returns home to find his living room in shambles after some sort of scuffle. As detectives start to investigate her disappearance, it appears that Nick, the dedicated husband, may have killed his wife. Fincher, Flynn and the cast, also including Neil Patrick Harris (portraying Desi) and Tyler Perry (portraying attorney Tanner Bolt), gathered at the AMC Loews Lincoln Square theater on Friday to discuss the film with attending press.

“We wanted to give truth to Gillian’s really dark look at marriage and David’s subversive take on the dark look of marriage," said Affleck, and in many ways, 'Gone Girl' might not have been a successful adaptation without Fincher at the helm. "I, at this point in my career as an actor, have decided that it’s all about the director ... David’s also, despite his reputation, a very funny and nice guy, not just a demon."

For Flynn, this sense of humor was an important element for 'Gone Girl,' and as she was waiting for a director to be announced, she was hoping Fincher would be the one to take the job. "I think he’s known for the dread in his movies and the claustrophobia and sense of place and all these things, but he’s underrated for these weird bursts of humor that are in his films. And I thought this would be the guy to keep those in there, and I think those moments are really important, particularly with the media," which she says is the manifestation of how our culture consumes tragedy as entertainment.

"We’re talking about a very narrow bandwidth of tragedy vampirism," followed up Fincher. "I’m not convinced that CNN and New York Times are in the flowerbeds at the Dunne house."

Part of what makes the novel 'Gone Girl' such a hit is Flynn's mastery of mind games, playing with the reader's perception of what's actually going on, and who both Nick and Amy actually are. When you pair her up with one of cinema's own master of mind games, it makes for an interesting, suspenseful and, at times, disturbing film.

“We put a marriage under a microscope, don’t we?” said Pike. "It seems to be a film about that intimacy, really, and the wonderful things that can go with intimacy, and the treachery that can come with intimacy when you know someone so well that you can just screw every little, sort of, nut."

As for Affleck -- who, Fincher hinted, was offered the Nick Dunne role by Fox before the director signed on -- was interested in the "ugly things" you discover when you ask the hard questions about marriage and your spouse.

I’ve seen very different reactions to the Nick character. It’s complicated. He does change but a lot of that has to do with the audience’s perception of him changing as they learn more about him. I don’t think you can play anybody that you think is a dick because then you’re not gonna do a very good job. So my job was to empathize with him. And really what I found is that women and men have a very different reaction to this character. Like, most of the women journalists go, [donning a flamboyant voice], "What’s it like playing a dick?” And most of the men just kinda go like, [Deep breath] "… Yeah."

If you were one of those people heavily criticizing the actor's casting in the upcoming 'Batman vs. Superman' movie, and concerned over whether or not he could follow Christian Bale in playing such a dark and mentally scarred hero, his performance in 'Gone Girl' will ease these fears. As our own Mike Ryan puts it, "This is the best ensemble I’ve seen in a film this year."

Pike, for one, was remarkable, mesmerizing and haunting in her portrayal of Amy Dunne. Much like the character, the actress herself made it difficult for Fincher to define. "There was opacity there and it was interesting. It wasn’t confounding; it made me lean in," he said. "We were in St. Louis, and we talked for about three hours before something donned on me, and I asked her. I said, “Do you have any siblings?” And she said no, she was an only child. She told me about her childhood, and I realized the person who plays Amy has to have that ‘cause it’s this hermetically sealed, you know, socialization."

“Weird kid," joked the actress, to which Fincher responded, “Just…off."

[Editor's Note: Be warned that Rosamund Pike's statements in the below paragraph could be considered mild spoilers, but spoilers nonetheless, especially if you haven't read the book.]

Wearing a black dress and matching black heels with a flash of bright red in the soles, Pike spoke about portraying such a devilish character, saying, "I have to tell you, it became incredibly fun. Obviously, [Amy's] playing different things to different people and, in a way, to the audience, too. But at the beginning, it was terrifying, before you’ve played the real Amy to then play the persona she’s created, another persona she’s created, was very daunting."

Both Affleck and Pike underwent various transformations over the course of the film, both mentally and physically. While Pike had to both gain and lose weight for various scenes, Affleck joked that he was only getting bigger.

“Ben was becoming Batman before my eyes," she said. "By the time we were in the shower [during a scene], I was with Batman.”

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