It takes all of two minutes of listening to Emily Blunt's voiceover in The Girl on the Train before you have to wonder whether this narrator might be unreliable. As her Rachel rides Metro-North in and out of Manhattan, detailing her obsession with the ostensibly perfect couple she steals glimpses of outside their two-story home each morning and night, the red flags pop up. What is she projecting onto these two that she lacks in her own life? The answers are coyly withheld in this adaptation of Paula Hawkins' novel directed by Tate Taylor, who has brought the page-turner to screen with all the unexciting competency of a commuter-rail dispatcher.
That beautiful young wife isn't a perfect stranger to Rachel, of course -- she actually lives two doors down from, and works as a nanny for, our forlorn train rider's ex-husband (Justin Theroux) and his new wife (Rebecca Ferguson). And then the first twist: The object of Rachel's projection goes missing the same night that she herself blacks out.
Blunt often shines in roles that rarely seem written as showcases. In her early scenes, she forgets an important rule of portraying drunkenness: She comes across as a sober person pretending to be sloshed rather than a drunk trying to act sober. But Blunt's great skill shines through once Rachel takes it upon herself to act as detective. It's as if the movie itself wakes up hungover 20 minutes in and spends the next hour and change reconstructing the events of the night in question piece by piece. That's an all-too-common means of slowly teasing out story information in mysteries, but at least form matches content here.