It's not easy to transition a story from book to screen, and "The Girl on the Train" is the current example for this.

The mystery in the said movie is nearly impossible to decipher if you haven't read the best-selling novel.

Emily Blunt leads the said movie and portrays Rachel, a woman who rides the Metro North train from New Jersey to New York City, looking into houses along the tracks.

She looks on one specific couple, watching them each time the train passes their home. She's also an alcoholic and recently divorced from her husband (Justin Theroux), who cheated on her.

The story has a lot of mysteries and going for it despite its confusing beginnings. According to Global News, the twist, which occurs suddenly toward the film's last quarter, isn't obvious and won't be clear to even the greatest movie sleuths. But it's worth it, watching Blunt's drunken character stumble through foggy memory after foggy memory until the realizations hit.

In an interview with The Huffington Post, Blunt cleared a few things up.

In terms of her biggest challenge with the movie, Blunt said that she "has never played somebody as tortured as this. It's such a challenge to play somebody in the grips of an addiction but also somebody who's afraid of themselves, and you've got the heightened environment with a potential murder."

Also, the movie is getting a lot of comparisons to "Gone Girl". Blunt feel that the main protagonists in the two movies are very different. There's one who's a sociopathic lunatic - Amy in "Gone Girl" - and then Rachel, who's a tortured alcoholic, who's a victim until she's not.

For the biggest question: How does Rachel get the same seat on the train every day? Blunt thinks maybe she actually does get the seat most of the time because she wants to get the perfect box to see her favorite house. Also, the actress said that the "the viewers are led to believe she's really living out in the sticks, so by the time she gets on the train, it's not very busy. Maybe she's at the end of the line, sort of an empty deal at that point."