An pulse-pounding, underwater adventure from the bestselling author of Darwin's Dragons! 'Real science is used to create mind-blowing magic, in an underwater world that will take your breath away – and give you gills instead.' LAUREN JAMES 'A simultaneously magical and visceral experience which kept me gripped until the last page.' DAVID OWEN 'A unique, thrilling read with twists that will keep you gripped until the very last page.' SARAH J. HARRIS 'Galvin is a thrilling storyteller, untangling a dense plot in brief, suspenseful chapters, her prose almost trance-like' TELEGRAPH When Aster wakes alone on a tropical island, she has no idea what has happened, why she is there, or where to find her younger sister, Poppy. Meanwhile Sam, who once met the sisters on a plane, makes links between the mystery of their disappearance and suspicious happenings in his own life. In a stunning dual narrative, the truth unravels with devastating effect – and the answer lies in the secret underwater world surrounding the desert island, populated by the beautiful and the impossible ... An excitingly original thriller for young teens by Lindsay Galvin, bestselling author of Darwin's Dragons. Pulse-pounding and mysterious, with the action split between the wilds of New Zealand and a remote tropical island. Fantastic plotting is enhanced by gorgeous, visual writing, vividly conjuring a tropical underwater world. Themes of bereavement, ecology, science and family.