Lizzie and her next door neighbour Evie Verver are inseparable, best friends who share everything. To Lizzie, the Verver household, presided over by Evie's big-hearted father, is the world's most perfect place. And then, one afternoon, Evie disappears. Driven by her desire to rescue Evie, Lizzie takes up her own furtive pursuit of the truth, pushing herself to the dark centre of Evie's world. As Lizzie uncovers secret after secret, she begins to wonder if she knew anything about her best friend at all.