If only this convoluted but interesting setup were any fun. Like Gone Girl, The Girl on the Train bounces between perspectives, including Megan's pre-trauma timeline, to maximize the surprises. But The Girl on the Train strains to wring suspense from the best-selling source material. Blunt, who's typically subtler than her name suggests, spends so much time sniffling, yammering, and panicked, you'd think she was starring in a presidential debate. Rebecca Ferguson, last seen kicking ass in Mission: Impossible - Rogue Nation, and Haley Bennett, last seen kicking ass in The Magnificent Seven, are stuck as floundering wives who do the opposite of kick ass.
The movie also idolizes Justin Theroux, Luke Evans, and Édgar Ramírez, the male counterparts winding up the women, as slabs of beef worth lusting over, despite not displaying any redeeming qualities beyond "looks good in Abercrombie." (You can almost understand Megan leaving her husband for a guy who can pull off Chelsea boots like Ramírez, but then you remember her eight tons of psychological baggage and go back to not buying it.)
Director Tate Taylor (The Help) can't counterbalance The Girl on the Train's horrors. There's no Lifetime original movie camp or the kind of sinister glee that can turn a horrifying crime into a hilarious Coen brothers movie. Instead, it's airport paperback therapy, where addiction, obsession, sexual hunger, and the plights of motherhood are curses to conquer through the cranking of an emotional vise. The script can't thread these plights through the central mystery because the central mystery barely exists; only after an hour of drowning in her own grief, and an hour of Taylor drowning the audience in the wavy slow-motion of '90s true-crime reenactments, does Rachel summon the fortitude to search for answers surrounding Megan's disappearance. Even then, she's her own worst enemy, and the revelations aren't satisfying (unless remembering blackout-intoxicated moments through a pounding hangover sounds like a blast).
But just when you've given up on the whole thing as being unredeemable, a twist ending comes along and makes you pay attention all over again. In fact, The Girl on the Train's greatest mystery is how it could fail so hard yet have an ending that's so damn good.
Consider this a big old spoiler warning: click away now if you don't want to know how this movie ends.