British actress Rosamund Pike got a front row seat to Ben Affleck's transformation to Batman while playing his wife in new thriller Gone Girl.

Director David Fincher called on his stars to lose and gain weight for thriller Gone Girl, which was shot out of sequence, but agreed to let his leading man bulk up as filming came to an end so he would be in shape to play the Caped Crusader in the Man of Steel sequel.

Pike tells Wenn, "We did jump back and forth and a lot of it was dictated by the weight fluctuations that had to occur for our characters. I had to be heavier and slimmer in all the different locations.

"But he (Affleck) was becoming Batman. By the time we were in the shower scene, I was with Batman!"