How often have you stared out of a taxi or bus window, witnessing some moment—a meeting, perhaps, or a person shouting into their phone—and wondered what the deeper story might be? Who are they? Why are they upset or happy? To the curious, people-watching can be one of life’s greatest enjoyments. In Paula Hawkins’s The Girl on the Train, it becomes one of life’s greatest dangers.

The book follows protagonist Rachel Watson, a divorced alcoholic, as she commutes to London. Every day, the train passes her ex-husband’s house: one he now shares with his new wife, Anna. Every day, Watson watches the house pass, and aches for her old life, for all that she’s lost.

But there’s another house that Watson also watches: a home down the street from her ex-husband’s residence, owned by a young couple she’s nicknamed “Jess” and “Jason.” They often sit on their terrace in the mornings, and so Rachel’s gotten used to watching them—to the point that she feels as if she knows them. They’re a stand-in for all the domestic bliss she dreams of. “They are,” she thinks, “a perfect, golden couple.” That’s what she thinks, at least, until “Jess” (actually named Megan) disappears—and suddenly, her “golden couple” fantasy falls apart.

Watson starts out as an incredibly passive protagonist. She rides the train aimlessly and watches houses pass: deep in her pain, and usually deep in alcohol. She is a rather pitiful character, falling into drinking binges time and time again. As the novel progresses, she slowly becomes more active and purposeful—but she also falls back into those old habits with a painful consistency.

Huffington Post writer Claire Fallon compared the novel’s themes and feel to Gillian Flynn’s Gone Girl, and I can definitely see the resemblance: both books focus on protagonists that are really flawed, broken, often unlikeable. But that also makes them incredibly human, and it makes The Girl on the Train authentic in a way few thrillers often are. We have no perfect damsel in distress, with serene good intentions and stunning beauty. Instead, the book’s stars are a trio of women with problems ranging from alcoholism to depression, from utter arrogance to complete emotional vulnerability. Watson’s unrequited desire for a baby and perfect family life leads her into a downward spiral of alcoholism and guilt; Megan’s tragic past and incessant panic attacks steer her toward sexual unfaithfulness; Anna’s vehement drive to preserve her domestic status and “perfect life” feeds her habits of cruelty and unkindness.

The men in Hawkins’s book mostly reflect the same sort of personal nuance, though there are a couple who seem to display a sort of one-dimensional badness. Hawkins is writing about misogyny and callousness, the sorts of relationships that break us down rather than building us up. It seems that in doing so, she’s tempted into creating villains that are occasionally cartoonish (though their impulses and words still display moments of ringing truth).

The Girl on the Train is refreshing and thrilling for many of the same reasons Gone Girl was: it contemplates the worst parts of ourselves, and shows the brokenness and sin that result from our self-centeredness. Unlike Gone Girl, however, Hawkins more fully contemplates the ways our love often gets tangled up in our brokenness, and how our emotions often lead us down paths we may regret later. The characters are less hyperbolic and unbelievable than Gone Girl’s (though that’s half the appeal of Flynn’s novel, so I’m not faulting her for that). Additionally, The Girl on the Train is less over-the-top in its plot—and purposefully so. In a Q&A with CBC News, Hawkins said, “The kind of crimes that happen in very mundane, ordinary, domestic settings, the kind of crime that could happen to all of us, the things that could be happening behind your neighbours’ doors — those are the things that I find intriguing and compelling rather than spies and serial killers. I’m interested in the domestic, everyday, ordinary and quite sad violence that goes on around us.”

In light of this, the book’s ending does seem a bit over-dramatic—it seems almost incongruous with the slow, gentle build of the rest of the book. But it doesn’t spoil the rest of what is an enjoyable, well-constructed novel.

It’s that combination of subtlety and surprise that seems to have kept The Girl on the Train atop the bestseller’s list since the beginning of the year—and now, will pave the way for a film adaptation next year (starring Emily Blunt). It’s a book about women, and in many ways for women—it’s a challenge, perhaps, to those who allow themselves to get trapped in their brokenness. But I also think it’s a book that anyone who has struggled with addiction or heartbreak can find relatable.