Sissy is used to being on the outside. The new kid at school, in the West Country of England, she observes the other girls like they're foreign creatures. At home, her troubled mother lets Sissy fend for herself.

But after Sissy fights a boy in the playground one day at school, she's no longer alone. Thrown into a secret friendship with the charismatic, apparently fearless, Tegan, the unlikely pair grow so close they feel like one being, wrapped around each in bed at sleepovers, sending photographs to men they meet in the online chat rooms of the 1990s, and scaring each other with reports of the girls being snatched at night in their small town.

On the precipice of girlhood, Sissy learns there's danger in both being desired and desiring too much. As past traumas return to haunt her and Tegan, and present-day threats circle ever closer, growing up seems like the only way out. But a "ritual" to beckon their womanhood has unintended consequences. In its aftermath, as Sissy's make believe world bleeds into her daily life, she feels her body transforming into something strange and terrifying.

With deft notes of magical realism and a constant psychological acuity, Amphibian is a tender, haunting coming-of-age debut, about desire, precocity and the intensity of early friendships that have the power to upend our lives.