On her first day at another new school in 1993, fourteen-year-old Rachel Walsh is the pale-skinned, overweight redhead searching for a seat in a new classroom, eventually drawn to the back row where she sits next to Clara O’Connor, the most popular girl in class. An unexpected moment—a look between two girls—and a friendship is born, one that smoothes all of Rachel’s rough edges, kindred soul Clara the other half to her whole, giving an imprimatur to the status of the new girl.

Though her mother left when she was a baby, Clara’s father dotes on her, arranges his schedule to accommodate his daughter’s needs, Clara the center of his world. Rachel’s mother, on the other hand, is bitterly disappointed by her life, never failing to remind her daughter that she is the fruit of a drunken one-off in an alley outside a pub, Rachel’s insufficiencies a daily reminder of a stupid mistake. No matter how she tries, Rachel can never please her mother, Niamh, who spends most days in an alcoholic stupor.

The relationship with Clara adds a new dimension to Rachel’s life, allowing her to partake for the first time in the emotional rollercoaster of early adolescence, the shared experiences of best friends. As the girls grow closer, Niamh, ironically becomes attached to Clara, welcoming her into their messy, chaotic home, someone new to distract her from chronic discontent. The motherless Clara obliges, stepping happily into the affection denied to Rachel. Niamh’s death on the eve of Clara’s eighteenth birthday drives a wedge between the friends, resulting in a separation of seven years before they reconnect.

Fast-forward to London in 2007, where Rachel is a crime reporter with a healthy career and a man who loves her unconditionally. Assigned to cover the story of a missing person in Brighton, Rachel is blindsided when she realizes that person is none other than Clara O’Connor. The nightmare begins, an unfolding mystery of where Clara has gone, CCTV showing images of Clara with Rachel’s boyfriend on the night of her disappearance. A series of text messages and an aborted meeting with Clara at a pub the night before create a troubling scenario that puts Rachel in the center of the mystery and directly in the sights of the police investigation, especially after a body is found, yet another element of the tragedy. Where is Clara, and who is behind her disappearance?

With well-placed psychological parries and thrusts that segue from 1993 to 2007, McBeth weaves a wicked tale of suspicion, deceit and murder as the tangled lives of two girls who share an extraordinary bond, each vulnerable to the other, turn from loving to contentious. In the midst of grief, chaos and the suspicions of the authorities, Rachel is forced to withdraw, clear her mind and remember what she knows is true, unraveling the taut threads between past and present: “You must have loved me a lot to hate me this much.” Her life depends upon it.

Shifting between the early years when Clara and Rachel fashion a private world of their own and the unfolding drama of a police investigation, McBeth explores the unique nature of girlhood friendship, the sensitive territory of secrets and the emotional terrain of a mother’s love—or the lack of. On the cusp of a revelatory denouement, the truth is finally laid bare in all its ugliness. But there is just a frisson of doubt: what if…