Twelve-year-old Molly Pecksniff wakes up one night deep in Tanglefern forest - unaware of how she arrived there. Because Moll has been lured there by a nightmare, the one with the drums and the rattles and the masks that calls to her every night. And this is the night that Moll will realise she and her wildcat, Gryff, are named in an ancient prophecy that has been part of her family for generations and that a witchdoctor Skull is out to destroy. Suddenly, Moll finds herself on an adventure she would never have imagined, with secrets and magic at every turn. But with the help of Gryff, her friend Siddy, and Alfie, an unlikely ally from Skull's gang, Moll is determined to fight back and fulfil the prophecy before it's too late...