EMILY BLUNT

The Into the Woods actress, 33, stars in The Girl on the Train, opening Oct. 7. The film is based on the New York Times best-selling thriller about a divorced woman whose already messy life is sent into a tailspin after she becomes obsessed with a woman she sees every day outside the window of her train.

Describe your Train character, Rachel Watson. I’ve never played someone who’s living in such a dark, toxic place physically and emotionally. The great challenge is to play an alcoholic in a realistic way. I don’t worry if she’s likable or not—I worry whether I understand her and you understand her. It was a bit of a departure for me, which is always appealing.

Rachel fantasizes about a couple she observes through the

train window. Can you relate? I am a people watcher. When I took the subway or the train all the time, I used to look at people and wonder what their lives were like, so I definitely have that voyeuristic urge in me. I like to sponge up what I see, put it in a bank and, hopefully, use it at some point.

How do you feel about playing Mary Poppins in Disney’s Mary Poppins

Returns, set for 2018? It is daunting. No one could outdo Julie Andrews, so I just have to try and do my version. I was thrilled by the idea and also slightly frozen with fear, but I feel much more on top of it now.

Do you and husband John Krasinski talk about working

together? We do a lot. I think we’d either like to do a play together, or a film where we’re not necessarily romantically involved. It would be cool to do something like Catherine ZetaJones and Michael Douglas did in Traffic, where they’re playing different parts but are part of the same film.