Image Source: Getty / Donna Ward [1]

When The Girl on the Train [2] made its debut on bookshelves in 2015, you could practically hear Hollywood execs already salivating over Paula Hawkins's dark, twisted story [3] and the vivid, broken characters she splashed across its pages. Because we all deserve good things, her novel's highly anticipated film adaptation [4] has finally arrived, and the devastating, disturbing thriller does its source material justice. We talked to the author about what it's really like to have something go from her head to the page to the silver screen and why Emily Blunt was the perfect choice [5] to play Rachel.

POPSUGAR: As an author, what has this whole process been like, seeing your characters and your story come to life on the big screen?

Paula Hawkins: It's been wonderful, and quite strange, obviously. The characters that you created wandering around in the flesh. In some senses the film feels like a very different thing, a very separate thing to the book. I don't mean that it's fundamentally telling a different story, but it's a cinematic retelling of the same story, so there is a distance between the two things. I'm really thrilled with it, though, and I think it's a really fantastic retelling and I think they've adapted it really well, and it wasn't necessarily a particularly easy book to adapt. There are certain aspects of it that are very obviously cinematic, but then there are other parts that are happening inside of a character's head, that you need to tease out in a visual way.

PS: What was your reaction to hearing that Emily Blunt [6] had been cast as Rachel? Did you have any say in who was cast?

PH: I didn't, but I was delighted that they chose Emily Blunt. I've always liked her as an actress. She has amazing range and takes on very different and interesting roles. I think she has done just the most extraordinary job in this film. It's really not an easy thing to play a drunk without making it look ridiculous, or kind of silly, or laughable. She's brought out all the sadness, and the kind of desperation and shame that's so central to Rachel's character. She pulls it out in quite a physical way, you can see her carrying it around with her. In her expression and the way she speaks, how her eyes appear to glaze over at points . . . I just think it's an extraordinary performance.

PS: While watching the movie, it almost felt to me like Rachel's messiness had been scaled back a bit from how out of control she was in the book. Blunt's performance was definitely subtler than I was expecting, and she felt more like a victim right away. Do you think it was a conscious decision to tone down the movie version of Rachel?

PH: I think you do get glimpses of how messy she is, but yeah I suppose that in a movie you've got to get to the heart of things a little bit quicker. You don't have the same space to develop. The start of the book is actually quite slow, and they don't have the luxury of doing that on film. Perhaps you get to more of the core of her suffering a bit earlier, but I also think the viewer will respect her for longer. In some ways she's a more threatening character for longer. You really start to wonder whether she's done something terrible.

Image Source: Everett Collection [7]

PS: Did anything surprise you about the film when you saw it for the first time?

PH: I don't know about surprising, but it is sort of beautiful. But then I knew it was going to be beautiful since I'd seen the locations they had chosen when I'd been to the set. But it doesn't look like what was in my head, the grubby London suburbs I'd pictured. It doesn't look like that. Although I really like the way it looks, because I think that heightens the contrast between all the grubby stuff that is going on behind the scenes. There were lots of small surprises, of course, but overall I think it's actually a really faithful telling of the story.

PS: What did you think about the movie adaptation being set in New York as opposed to London?

PH: I think they just decided that [setting it there] would reach a much bigger market, and they felt it would work over there. And I think it does! I think the sort of essential location is really the train. It's not necessarily what city you're going to. In the book London isn't that important, just like in the film New York isn't important. It's that going backwards and forwards, and seeing those little suburbs on the outskirts. Those could really be anywhere, because those kind of suburbs are the same the world over.

PS: Maybe your opinion has changed now that the book has been out for a while, but of the three central women in the story, which one was the most fun for you to write?

PH: Rachel is the one that I felt closest to in the sense that I had been thinking about that character for a really long time, and I felt like I knew her best. In a way, actually writing Anna was quite fun because Anna, well, she's kind of a b*tch, and writing those people is fun. She was more enjoyable, because being in Rachel's head was a bit miserable some of the time. Anna was more like a relief.

Catch The Girl on the Train when it hits theaters on Oct. 7.