Mara's island home is drowning as the ice caps melt and Earth loses its land to the ocean. But one night, in the ruined virtual world of the Weave, Mara meets the mysterious Fox, a fiery-eyed boy who tells her of sky cities that rise from the sea. Mara sets sail on a daring journey to find a new life for herself and her friends - instead she discovers a love that threatens to tear her apart ...

"The world is gradually drowning, as mighty Arctic ice floes melt, the seas rise, and land disappears forever beneath storm-tossed waves . . ." Sixteen-year-old Mara and her ship of refugees are tracking the North Star, desperate to find a homeland in the melted ice mountains of Greenland. The vast, floating city of Pomperoy is just one of the shocks that are not in their navigation plans. Unwittingly, the refugees bring catastrophe in their wake for Tuck, a gypsea pirate-boy, and also for Ilira - a land whose inhabitants exist in a state of terror at the top of the world. Back in the drowned ruins at the feet of the towering sky city, Fox is beginning his battle with the cruel, corrupt forces that rule the New World. But separated from Mara, his resolve begins to waver . . .

Much of Earth is underwater in the high mountains at the top of the world Lily survives with her mother and her people ...but she feels trapped. Elsewhere, beneath the exclusive sky-cities that tower above the waves, Fox has been waiting too. But when Fox and Lily meet on a virtual plane, they realize the time has come to act. The world must be made whole again, even if it means losing each other! The third and final installment in the brilliantly imagined, hugely romantic and poetically told trilogy set in a frighteningly realistic future.