The relationships we form in college can last a lifetime, for better or worse. For Kate Channing, it might be for worse. Ten years ago, she and five Oxford friends spent a week celebrating their graduation at a farmhouse in France. The trip should have been an idyllic capstone to their college careers. Instead it was marked by betrayal, infidelity and, most tragically, the disappearance of Severine, the “slim and lithe…mademoiselle next door." The 19-year-old French girl of the title of Lexie Elliott’s debut novel vanishes the day the friends return to England, the last trace of her caught on some grainy CCTV footage in a nearby bus station.

Kate, now a successful professional with her own legal recruiting firm, has largely put the unpleasant incident behind her. But the wounds over the breakup with her college boyfriend Seb, which occurred during the same ill-fated vacation, are still raw. Then dapper French policeman Alain Modan shows up in London with some disquieting news. Severine's body has been discovered in a well on the farmhouse property. What was once a dormant missing persons investigation has become a murder inquiry.

"[T]he question of which of these outwardly normal people is a cold-blooded killer is enough to keep the pages turning."

Every member of the old gang is a suspect: Seb, married and recently returned to London from New York; Tom, Seb's (slightly) poorer relation who is now a successful currency trader; posh and snobbish Caro, an ambitious lawyer; and Lara, Kate's sweet and sexy Swedish best friend. (Theo, the other member of the group, has since died.) Over the years, the once-tight circle of friends has drifted apart, but the reopened investigation necessitates an awkward and unhappy reunion. Modan's persistent questions about what really happened in the days before Severine vanished exposes old fractures and pits the former friends against each other.

Elliott has a keen understanding of the subtle intricacies of social dynamics and the way old slights can fester for years. She skillfully highlights how Kate's state-school education and Northern upbringing mark her as a perpetual outsider among her more privileged friends, despite the shine of her Oxford degree, as well as the way she layers her own misconceptions onto the friendship between Lara and Tom, who had a brief fling a decade ago. Despite being 10 years on from college, she can’t stop dwelling on what her friends really think of each other, and what they think of her. Case in point: She still hasn’t forgiven Seb for betraying her, even with “ten years and a bloody marriage ceremony” in between, and her distaste for Caro, who has always treated her with a thinly disguised condescension, is palatable, though when the novel opens she hasn’t spoken to her in years.

For Kate, finding out what really happened to Severine allows her to finally move on from the past. In fact, the big mystery purportedly at the center of THE FRENCH GIRL takes a backseat to the unfolding drama in the present day. There are no flashbacks to the trip to the farm or conversations with those who actually knew the dead woman intimately. Elliott offers a cursory explanation of the how and why of the murder, instead focusing on the way the friends gradually turn on each other as the investigation drags on. At times, it seems like Severine’s primary function is to provide the novel with an on-trend title. That’s not to say she’s not a presence throughout the book. She regularly appears, silent and smirking, to Kate in a series of visions that become increasingly vivid as the whodunit heats up, eventually pointing to her killer. As a victim, however, she is disappointingly flat, a beautiful, enigmatic young woman cut down so that the others can learn something about themselves.

While Severine leaves something to be desired as a character, Elliott does excel at sowing reasonable doubt about the identity of her murderer. Everyone is a plausible suspect in this slow-burning thriller. Back stories are revealed bit by bit, until the pieces finally fall into place. Even when Kate’s internal drama gets a bit tedious at times (as an accomplished 30-something woman, isn’t it time she just get over her college boyfriend?), the question of which of these outwardly normal people is a cold-blooded killer is enough to keep the pages turning.