Michelle Williams has revealed she feels she is being taken over by Marilyn Monroe's character while making her new film.
The Brokeback Mountain star is playing the screen icon in new film My Week With Marilyn and told the Daily Mail she has become so immersed in the role that she doesn't feel quite herself.
Michelle said: "I feel like we live together.
"At a certain point, something else does take over. I don't quite feel myself these days."
The film is based on the diary of Colin Clark who worked as Laurence Olivier's assistant on The Prince And The Showgirl in 1956, which starred Marilyn Monroe and Olivier, who also directed.
Michelle, 30, revealed she initially turned down the offer of the part from director Simon Curtis.
But she said: "I knew I wouldn't be able to resist, eventually.
"Physically and vocally, everything about her is different from me. I've kind of gone to school and had teachers to help me understand Marilyn, so I could project an essence of her.
"It rearranges you, it shifts your molecules, lifts you up, spins you around, puts you back down and you're not quite the same, for better or for worse."