Watch Emily Blunt as a Murder Suspect in ‘Girl on the Train’ (Trailer)

Blunt plays a vital role in the disappearance of a woman in the Justin Theroux-starring thriller

Last Updated: July 18, 2016 @ 7:27 PM

Emily Blunt takes a chilling turn as a newly divorced woman who becomes fixated on a “perfect” couple in the upcoming thriller “The Girl on the Train.”

In its just-released new trailer, we see a lonely and depressed looking Blunt, who finds herself caught up in the middle of a possible murder mystery love triangle.

Blunt plays Rachel Watson, a troubled woman who becomes fanatically obsessed with a couple, whose house she passes while on the train every day on her way to work. That couple — her ex-husband’s (played by Justin Theroux) next door neighbors, Megan and Scott Hipwell. Mrs. Hipwell (Rebecca Ferguson) also happens to be the ex-husband’s hot, blond nanny. And, you guessed it, the sexy duo is having an affair.

When Mrs. Hipwell (aka the nanny, aka the mistress) suddenly disappears, all eyes turn to Watson and her involvement. In the clip, we see her attempting to help in finding out what happened to Hipwell, although it’s clear that her help isn’t wanted. At least, not by her ex-husband it isn’t.

The trailer also shows Watson examining mysterious bruises and scrapes on her body, not knowing how they got there. The deeper she digs into Mrs. Hipwell’s disappearance, the more her involvement becomes suspicious.

“The Girl on the Train” is directed by Tate Taylor and will be released in theaters October 7.

Watch the video above.