From page to screen: Does The Girl on the Train follow in the novel's tracks?

To say there are high expectations forthe movieThe Girl on the Trainis a bit like saying the story's protagonist, Rachel, likes to have a drink every now and then: aconsiderableunderstatement.

The debut novel by Paula Hawkinswas a runaway bestseller in 2015, with more than 11 million copies sold to date. Movie rights were snapped up before the book even hit the stores.

So does the film live up to the book'spage-turning, chock-full-of-twists reputation?

• VIDEO |The Girl on the Train author Paula Hawkinstalks success, suspense and the future
• FILM REVIEW |The Girl on the Train, The Birth of a Nation and more

What worked really well: Emily Blunt as Rachel

British actress Emily Blunt really can do it all, from eye-rolling cattiness (The Devil Wears Prada)to alternating fragility and toughness (Sicario).She shows the same commitment to the role of Rachel,the alcoholic, messy, voyeuristiccentral narrator of The Girl on the Train.

It's a tough roleto perform and to watch as Rachel wobbles between self-loathing to manic activitybut Blunt delivers it with aplomb. Her beauty is difficult to conceal (make-up and wardrobe departments do their best to depict neglect with smeared eyeliner and unfashionable pants), but at no point does Blunt'snatural elegance detract from the role. Viewers are humiliated for Rachel, rootfor herand are frightened of her all at once: it's the essential unreliability that made the character so compelling in the novel.

What worked well: other casting

Justin Theroux might finally come out of the shadow of being Jennifer Aniston's husband for his role as Tom, Rachel's ex who left her for Anna,another of the story's point of view characters.

Luke Evans is equally compelling as the sexybut tempestuous Scott: his potential for violence simmersin every scene. Kudos to director Tate Taylorfor making Evans' muscle-bound physique anobject of lust for both Rachel and the camera staying true to the book's female gaze.

Hailey Bennett, who portrays the third female narratorMegan, is a less obvious casting choice. The book consistently describesthe character as frail and petite, her physicality connoting the "wounded bird" Megan is underneath. Tall and athletic, Bennett oozes vitality that's a little difficult to reconcile with Megan's frailty. But Bennett lends the character angst and rage that are compelling to watch.

Still, it'sa pair of actresses in smaller roles whoreally dazzle: Allison Janney as the poker-faced detective Riley (a role bigger in the film than in the novel)and Lisa Kudrowas a sympathetic acquaintance who steers Rachel towards truth about her life. Both are excellent.

What didn't work: a change oflocation

One of the things that made The Girl on the Train stand out was its essential English-ness.

Rachel commutes daily from a small town to London; glancing at brownstones and Victorian houses dotted along the way. She's an adult, but she lives with a roommate. Her drink of choice is a gin-and-tonicthe pre-mixed variety found at any British corner shop. These details paint a realistic portraitof middle-class England, but seem somewhat out of place in the movie'sAmerican setting.

One can only surmise that the filmmakers changed the location to appealto a U.S. audience, but the decision stripssomething of the soul of the story, and makes the movielook more like Gone Girl minus David Fincher's direction.

Also inexplicable: despite the shift to New York,Rachel's still aBrit,which is only briefly referencedbut never explained.

What didn't work: the structure andpacing

The Girl on the Train's narrative structure was one of its defining characteristics: the story is told bythree women (Rachel, Anna and Megan), each of whom revealsand conceals details in her respective account.Plus, the story unspoolsasa nonlinear narrative. That's fine in a book when you can flip back and forth, but sticking to this structure for the film version createsplot confusion.

The Girl on the Train movie depictscharacters especially Anna and Megan superficially, never truly touching ontheir motivations. Whereas the novel slowly revealsthelayers of each narrator's inner demons, in the film they're unceremoniously dropped on viewers,who don'treally have time to absorb it all, nor connect to the characters.

All said, The Girl on the Train moviehas its charms: it's entertaining and well-shot, withlively performances that keep it ticking along. Ultimately, it may be a better fit for those who haven't read the novel than readers waiting to see a favouritebook brought to life onscreen.