Emily Blunt's Rachel Is Tormented in Ominous New 'Girl on the Train' Trailer

"I don't think you're helping anybody."

The new trailer for upcoming thriller The Girl on the Train gives viewers more of a glimpse into the lives of the characters in the film, which tells the story of Rachel Watson and her involvement in a mystery surrounding missing woman Megan Hipwell.

"I used to watch this perfect couple and they were the embodiment of true love," says a forlorn Rachel, played by Blunt, as the trailer begins.

When Megan goes missing, Rachel tells her ex-husband Tom (Justin Theroux) that she's trying to help find her. Megan also worked as a nanny for the child Tom has with his new wife. "I don't think you're helping anybody," says Tom.

There are shots of a woman getting pulled back by her blond hair, snaps of different scenes at times aggressive and other times highly sexual, mixed with scenes from the investigation and Rachel's questioning. Viewers learn that Megan had a therapist and that her husband seems suspicious of him. All of the suspense builds as Kanye West's "Heartless" plays in the background.

The Tate Taylor-directed movie, based on the bestselling novel of the same name, hits theaters Oct. 7.