When twelve-year-old Oscar Dare moves from London to Ireland, his expectations are far from high. But when his family visit their new house near the legendary Giant's Causeway, Oscar ignores the warnings the locals give about swimming there at dawn and dusk, and would have drowned if not for a mysterious girl with a strange name and a hidden legacy. She is Terranova- the embodiment of the new earth, one of the three magical beings that hold the boundary between the spirit world and the normal world; a line that is thinning already. Four years later, at sixteen, his explanation for his rescue is still written off by psychiatrists as a drowning hallucination. But Terranova is as real as the land itself, and people other than Oscar know it too.