Will believes in witches and the stories he's grown up with - of mythical storm-lions, disappearing villages, and secret songs. Most of all, he believes the tales of magical treasure hidden in the Fens centuries ago. Treasure that he has to find, to solve the mystery of his Ma's disappearance. Then, in the eye of a storm, a witch arrives. She holds the key to finding the lost treasure: a powerful magical object that can summon storms. But someone else is searching for it too. If it falls into the wrong hands, Will's beloved home could be destroyed – and with it, his chances of ever finding his Ma . . .