The new mystery thriller "The Girl on the Train," based on the best-selling novel of the same name by Paula Hawkins, is a case of where its lead actress shines brighter than the film itself. Thankfully, that star belongs to the impressive performance of Emily Blunt ("Sicario") in an Oscar-worthy turn that navigates through the story's predictable paths. Rachel Watson (Blunt), an alcoholic who divorced her husband Tom (Justin Theroux) after she caught him cheating on her with his new wife Anna (Rebecca Ferguson), takes the train to work daily. She fantasizes about the relationship of her neighbors, Scott (Luke Evans) and Megan Hipwell (Jennifer Lawrence lookalike Haley Bennett), during her commute. That all changes when she witnesses something from the train window and Megan is missing, presumed dead. Taking its cues directly from the hit movie and novel, "Gone Girl," "The Girl on the Train" is directed by "The Help's" Tate Taylor and is a well-acted mystery with some nice twists and turns, blessed to have Blunt on board its train, as she embodies Rachel with a perfect imperfectness that carries this imperfect movie. The script, by "Chloe's" Erin Cressida Wilson, is faithful to Hawkins' novel with a few exceptions (namely, the locale is now New York City/Upstate New York instead of England), which is both good and frustrating; the exposition, similar to the novel, is presented from varying viewpoints then, a tricky move that works slightly better here, but also like the novel, it drifts off in its second act with too many different subplots and characters, and when it veers from Rachel's story, it becomes less interesting. Director Taylor would've been wiser to excise some of these for a leaner, more efficient film, though his talented cast certainly helps in the watchability factor. While Blunt carries the movie, Theroux is also solid as the ex-husband with secrets of his own, and Bennett has a couple of memorable scenes as the troubled girl whose murder is the central focus of the film; also watch for "Friends" Lisa Kudrow in a small but pivotal role of an ex-colleague who helps jog Rachel's memory just at the right time. Because of its muddled, unfocused plotting mid-film, I was prepared to give "The Girl on the Train" a C+, but I upgraded it because of Blunt's brave, mesmerizing performance - she's that good - and if you're prepared to jump on her starmaking bandwagon, you better hurry, it's faster than a locomotive.