"In the domestic world is where I think women can be quite cruel about each other, more so than any other environment," Blunt told THR.

Emily Blunt, Luke Evans, Rebecca Ferguson, Haley Bennett and director Tate Taylor arrived at the world premiere of The Girl on the Train on Tuesday night, where they walked on faux train tracks in lieu of a red carpet in London's Odeon Leicester Square.

The Universal thriller stars Blunt as a troubled woman (an alcoholic whose husband left her for his mistress) who becomes fascinated by a seemingly perfect couple whose home she passes while riding the train. But after she thinks she witnesses a murder, she begins to realize that she may have been involved in the crime.

As the novel and film touch on aspects of motherhood, Blunt — donning a bejeweled, floral Alexander McQueen gown — ironically shot the adaptation of the Paula Hawkins best-seller while still pregnant with her second child.

"I think women will really relate to it and see aspects of themselves, or themselves fully, in any one of these characters," she told The Hollywood Reporter. "There is a huge societal pressure on women when it comes to motherhood, and these 'mommy cults' that go on. It makes women feel that they have to be a bit defensive about the choices they make — whether they want to be a mother or whether they don't, whether they want to breastfeed or whether they don't. I could go on and on.

"In the domestic world is where I think women can be quite cruel about each other, more so than any other environment," she continued. "This film captures that."

Blunt herself is admittedly a fan of some true crime entries — "I loved The Jinx, and my father defends criminals for a living so it's definitely dinner-table conversation for us!" — but still needed to unwind after a long day of shooting the dark domestic thriller.

"I found a way to detach from the day — I had a long car ride home and would try to meditate on the way," she said of the December shoot in New York. Luke Evans agreed: "I had to go back to Manhattan — but no train for me!"

The Girl on the Train hits theaters Oct. 7.