Emi and Polly Leto are identical twins with a shared life—until Emi vanishes and Polly is left searching for what she has lost. Now one becomes two, and twindom becomes duplicity as myth and memory merge, forcing Emi and Polly to confront what they thought they knew about themselves and the parents who made them. Behind the twins is their creator, their mother Sarah, a mother without whom there would be no story to be told. From the edgy heart of London to a remote idyll on the Stockholm archipelago, this is a journey that explores the power of love, the damage wreaked by depression, and the agony of sexual deceit. It is a story about the genetic impact of nature wrestling with the heady demands of nurture, about patterns of behavior and the cruel turns of fate.