The practice of referring to grown women as girls continues; here is the one on the train, as opposed to the gone one, or the one with the dragon tattoo. Last year’s mega-bestselling thriller from Paula Hawkins has been adapted for the cinema pronto.

But this hottest of literary properties lands with a lukewarm splat on the movie screen: a guessable contrivance with a biggish plothole. Lieutenant Columbo could have sorted it in five minutes. The complicated web of narrator-switches, flashbacks and POV-shifts seems clotted and Emily Blunt – usually so witty and stylish – is landed with a whingy, relentlessly weepy role in which her nose hardly ever resumes its natural colour.

Blunt plays Rachel, a sad and lonely woman whose life has collapsed since the end of her marriage. She was with Tom (Justin Theroux), but the relationship was put under fatal strain by their failure to get pregnant. To add to her current wretchedness, Tom is now together with the woman with whom he was cheating on her: Anna (Rebecca Ferguson), who has given him an adorable baby. Now Rachel drinks vodka all day, obsesses about Tom and Anna, has rages and blackouts, and in a pathetic state of denial rides the suburban commuter train into Manhattan where she has long since been fired from her PR job on account of the booze.

But Rachel has formed a weird obsession: every day, from the train window, she glimpses scenes from the life of what looks to her like an enviably perfect couple: an unfeasibly gorgeous blonde woman and her handsome, devoted man (who turn out to be called Megan and Scott, played by Haley Bennett and Luke Evans). She fantasises about who these people are. But then she witnesses a shocking event; this woman turns out to have a domestic connection with Rachel, which is to lead her into a web of cruelty and murder.

The idea has promising resemblances to Alfred Hitchcock or Patrick Hamilton, and Hawkins could also have taken something from Agatha Christie’s detective story 4:50 From Paddington, in which someone looks out from their train directly into the carriage of one running alongside at the same speed, and sees someone being strangled.

The connection between Rachel and these two couples seems so close that it somehow looks as if they must surely live next door to each other in a row: certainly it’s a bit odd that if Rachel is as obsessed with Tom and Anna as she is supposed to be, wouldn’t she have quickly recognised this mystery blonde woman she’s seeing from the train window every day?

Then there’s the rather outrageous poses being struck by this handsome couple. Sometimes they’re cuddling together at night, in the back garden, around some sort of flaming brazier. The train does seem to come very close. The noise must be deafening. Maybe the property prices are lower to reflect the fact that sexually obsessed commuters will be eyeballing you every night. And in one startling scene, you see them in their Martha-Stewart-perfect kitchen preparing to have vigorous sex up against the fixtures and fittings. We cut back to find Rachel doing hardly more than gazing sadly at them. In real life, you’d have loads of pervy commuters of all ages crowding around Rachel, gawping with their noses pressed up against the window, filming it on their iPhones.

The plot thickens as Rachel cultivates a tense relationship with Scott, and with tough cop Detective Riley, played by Allison Janney, and with a certain dishy man called Dr Kamal Abdic, played by Edgar Ramírez, who is described as Haley’s “psychiatrist” – psychotherapist, surely? Other herrings of various hues are produced.

Emily Blunt does her considerable best with this exasperating and plaintive role. In movies from The Devil Wears Prada to Sicario, she has shown that she can look good while being ill or messed up: strong, believable, human, vulnerable. But this part doesn’t give her any scope for recovery, for the all-important mastery and survival: she just always looks under the weather. This doesn’t give her half the juice and outrageous fun that Rosamund Pike had from Gone Girl. Fans of Paula Hawkins’s thriller might find themselves sticking to the book.

• The Girl on the Train opens in the UK on 5 October and in the US on 7 October.