When director David Fincher cast Rosamund Pike in "Gone Girl," he asked that she model her performance as the movie's mysterious missing wife, Amy Elliott-Dunne, not on another actress or well-known icon but on Carolyn Bessette-Kennedy, the willowy blond bride of John F. Kennedy Jr. who died alongside her husband in a plane crash in 1999.
Pike paged through back copies of Vanity Fair and looked for video of the young woman who was to be her muse but ultimately found Bessette-Kennedy hard to know.
"It was interesting for [Fincher] to give me that reference because it's just image, there's nothing written about her by anyone who really knew her. There's nothing in her own voice," Pike said. "So I began imagining what it felt like to be posing as that fantasy."
The fantasy characters that women portray in their daily lives — and how exhausting they are to maintain — is a central idea in "Gone Girl," a stylish thriller about marital secrets adapted by Gillian Flynn from her bestselling novel of the same name. The movie, both a critical and box-office hit since its premiere at the New York Film Festival in late September, stars Ben Affleck as Nick Dunne, Amy's befuddled husband and the lead suspect in her disappearance.
For the first time in her career, Pike, 35, is at the white-hot center of a hit, and it's for a complex performance that required her to layer the ideal of a "cool girl," a modern archetype Flynn coined in her book, over a much darker core.
In an interview hours before the New York premiere, seven months' pregnant with her second child, the British actress confessed she hadn't slept the night before, suffering a mixture of jet lag, discomfort and excitement.
"I've never really been at the fulcrum of something quite as massive as this," Pike said.
She has, however, notched some experience as a fantasy woman, including the role that would introduce her to international audiences: the icy Miranda Frost in the 2002 James Bond film "Die Another Day."
Pike, born in London as the only child of two opera singers, had been acting in British television and on the stage when she booked that career-making part. She followed it with well-regarded supporting performances in a diverse array of projects: a Jane Austen adaptation ("Pride & Prejudice"), a coming-of-age period drama ("An Education"), a Tom Cruise thriller ("Jack Reacher").
It was that breadth of work that appealed to Fincher when he was looking for his enigmatic Amy.
"As someone who watches actors for a living, you get a pretty good idea of the arrows in their quiver," Fincher said. "And I couldn't get a bead on Rosamund. There was an opacity there that I found really interesting. I couldn't say, 'Oh, yeah, this is what she does,' because what she does in 'An Education' is very, very different from what she does in 'Jack Reacher.' ... She was totally at home in 1962; she was totally at home in a James Bond movie, in 'Pride & Prejudice.' I liked that you could spin [Pike's career] in light and it would refract different beams."
Fincher and Pike held a book club of two over Skype, discussing Flynn's complicated character as Pike unwittingly began revealing more of herself. When she visited Fincher in St. Louis, where he was location scouting, she shared a crucial quality she shared with Amy, that they are both only children.
"I was aware from our Skype conversations that something very unusual was happening," Pike said. "I felt that this man was reading me in a way that people often fail to do, that he was starting to see beyond the facade. To be honest, there is a Rosamund Pike facade that's not of my own making. There is a persona that I'm very aware of being out there which I never built.
"It's British, it's aloof, basically an image created by the 'Die Another Day' movie. I'd spend two hours talking to a journalist, and somehow the facade would not tumble. And yet when I was speaking to David, I thought, somehow this man is getting me and is seeing other things, and it's quite exciting. This guy knows I've got this character in me, and I don't know how he knows that, but he does. He's got a hunch about it."
Once Pike was cast, she had certain technical tasks to accomplish, including mastering a patrician, prep-school version of an American accent. Having grown up with musicians for parents, Pike has a particularly attuned ear, though she found the word "murder" especially challenging, with its two Rs.
Due to the shooting schedule, she also had to gain and lose the same 12 pounds three times over the course of a 100-day production, which she did with the help of a professional boxer.
"Amy has faked this life where she's eating a full pizza and remaining a size 2," Pike said. "In a way, gaining the weight is a sort of angry expression of what she feels about that image that she peddled for so long. She starts to negate it by eating cheeseburgers and fries."
Putting on a performance as someone who is effortlessly charming and skinny isn't so far from what many actresses are asked to do. Asked if both the delight and burden of assuming a persona didn't have a particular resonance for her, Pike said it did.
"When you're playing a character, you don't have to like her; you just have to get her," she said. "Whatever that says about you. You're always called upon to delve into some aspects of your psyche. Some of them will be the really fun bits to explore, and some will be the more troubling parts to explore. When you're playing this character who's a good manipulator, it leaves you with an uneasy feeling, 'cause she wields a lot of power, the way she convinces people, which is a kind of power one has as an actor too. It can make you feel unhinged at some point.
"But everybody basically has a facade," Pike said. "It's a fun game to play. Facebook licenses it, Instagram licenses it ... I don't actually do either. Just staying rooted in your true self amid all the hoopla can be the hardest to navigate."