Everybody loves a good whodunit. Not only is it delightful that “whodunit” is a legitimate genre and actual word, but mystery films are usually captivating by nature. Anybody with a normal life to get away from can appreciate a quest to uncover the perpetrator of a murder or some other nefarious deed.

Enter “The Girl on the Train,” a 2015 novel that was quickly hailed as “the thriller that shocked the world” (an over-exaggeration) and “the next Gone Girl” (haven’t read either). The book soon sold like the Bible but with more melodrama, so naturally we’re getting a film adaption one year later. Hollywood was perhaps a bit too proactive with this one: the film rights to the book were bought before the book was even released.

That speaks volumes about Hollywood’s confidence in this story’s target audience, and they’re probably right: “The Girl on the Train” will undoubtedly please anybody looking for a lurid mystery full of lies and loins, especially fans of the book — but anybody else will be disappointed by a film that’s too self-assured in its own shortcomings.

The Girl on the Train is so enamored with its own premise that it often fails to be anything other than a journey towards a twist. This works to both the film’s benefit and its detriment. On the plus side, the narrative thrives off of a singular focus that never strays into unnecessary territory. Every minute of the chronologically distorted, multiple-unreliable-narrators story binds together to create a whodunit that’s worth sitting on the edge of your seat for. Erin Cressida Wilson’s screenplay is admirable in its ability to take multiple loose threads (and cannons) and tie them into a neat bow of intrigue.

On the downside, the “shocking twist” is painfully obvious over an hour before you’re supposed to figure it out. My friends who have read the book claim it wasn’t so careless with the big reveal, but this overeager film reveals its hand far too early. There’s nothing shocking here.

The Girl on the Train’s biggest similarities to the film adaption of Gone Girl are its direction, tone, and color — but none of these aspects come close to David Fincher’s masterclass of tension. Tate Taylor’s ostentatious direction comes off as Gone Girl shoved through a Lifetime movie filter. The use of slow motion to constantly emphasize a dramatic point is egregious; the tone is dour but without respite through dark humor or any likable characters; the color grading is an Instagram filter of despondency. This is one dark, sad movie — but not imaginatively so. The despair only feels worth it at the very end.

Thankfully, Emily Blunt wades so deep into the gloom and doom that she practically saves “The Girl on the Train.” Her performance takes “ugly crying” and extends it to every facet of her character. I mean that as the highest of compliments. Pulling off a fully fleshed out human being can be difficult when she’s defined by torturous experiences, but Blunt handles this performance incredibly well and with raw physicality. The film’s writing often slips into unnatural sounding monologues instead of dialogue, which is sometimes the territory when adapting novels into movies. Blunt takes advantage of every word and transforms speeches into outpourings of emotion.

So should you buy a ticket? If you read the blueprint for this train and loved it, yes. If not, it depends on how much you like pulp mysteries. And Emily Blunt.

★★★ (3 out of 5)