It's a convoluted plot, and that's only summarizing the first act. The Girl on the Train film follows the format of the novel by splitting the storyline between Rachel, Megan and Anna's first-person perspectives; while it might have worked on the page, it's overly complicated on the big screen, and causes the movie to move at a snail's pace as it cuts back and forth between characters and timelines. The twists and turns of the narrative are supposed to be enough to move the story along, but ultimately they end up being familiar tropes that don't elevate the story beyond average thriller material.The Girl on the Train was pitched as this year's Gone Girl, but Gone Girl presented a much more harrowing and insightful look at marriage and the idea of the "perfect woman." The Girl on the Train flirts with interesting conversations about alcoholism, abuse, depression and a woman's desire for children, but the big twists in the third act undercut a lot of what was being set up and leaves the movie feeling hollow.
The biggest flaw with The Girl on the Train is that none of its three leads are especially likable. While there have been plenty of films that have had success in unlikable characters -- Gone Girl being one of them -- it doesn't work for Rachel, Anna and Megan alternately as a complicated web of mysteries and betrayals pull them closer together. Even when the curtain is pulled back on the traumas in Rachel and Megan's pasts, it doesn't do much to humanize them.That's because The Girl on the Train never does much to offer any of the three women much depth beyond their initial stereotypical depictions. Rachel is the unhinged, alcoholic mess, Anna is the bitter, shrewish, uptight housewife and Megan is alternately the girl next door, the ingenue and the slut. Though the plot gets developed in convoluted ways that offers new wrinkles to their stories, they never end up breaking from those character molds.
The great cast does their best to offer range to their one-dimensional characters, with Blunt doing most of the heavy lifting. The ponderous first act largely hinges on Rachel's alcoholism and obsession with the life she lost, and the responsibility of moving the plot forward is placed on Blunt's shoulders. She does her best with the material, getting deep inside Rachel's troubled headspace, but even she can't save the movie from itself.