The Girl on the Train: The terrifying scene that's not in the book 

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is a dark novel — full of alcoholism, adultery, and violence — but Tate Taylor’s film adaptation, in theaters Oct. 7 and starring Emily Blunt, is even darker. And there’s one brand new scene in particular that’s sure to chill viewers to the bone, and likely will become one of the most memorable of Blunt’s career.

Rachel Watson (Blunt) is spiraling out of control in a bathroom at Grand Central Station. Every day she’s been watching a perfect couple, Megan and Scott Hipwell (Haley Bennett and Luke Evans), from the commuter train she takes into New York City. They’ve renewed her hope in love after her own marriage has disintegrated. But earlier today, she saw something that’s sent her into an explosion of fury: Megan was with another man.

In the bathroom, Rachel careens into a martini-fueled rage, violently smearing lipstick across a mirror with both hands and screaming her desire to storm into the Megan’s house and grab the woman by the hair. “I would just smash her head all over the floor!” Rachel shrieks, voice cracking. Rachel has hovered just above her breaking point for weeks — but now, she’s finally shattered.

“It’s the peak of her unhingedness,” Blunt tells EW. “It couldn’t be sad, it had to be angry. You had to imagine that she could be capable of doing dangerous things.” She remembers shooting three or four takes, but she and Taylor knew they’d struck gold on the second one.

“I thought I was finished, but then there was just a little bee in my bonnet,” Taylor says. “I was like, ‘Goddamnit, she’s good, but…’ And I go, ‘Emily, let’s do it again! Now I want you to smear the lipstick all over the mirror!’ and she was like, ‘Oh my god, let’s do it!’”

For screenwriter Erin Cressida Wilson, creating this new scene for the film gave her an intriguing way to play with technology. Before the lipstick-smearing explosion, Rachel tries to take a selfie with a stranger-turned-drinking buddy, but accidentally takes a video – and leaves the phone filming from the counter during her breakdown. “She ends up recording what seems to be a testimony of a crime,” Wilson says. This apparent evidence seems increasingly damning when Rachel wakes up the next morning covered in cuts and bruises but with no memory of the night before – and according to the news, Megan has gone missing. It’s no wonder that Rachel’s greatest fear is herself.

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