1815 England. Shipwrecked off Ireland and landed at Watchet Harbour, Somerset - Esmeralda Grimm and her half-sister Fancy, set out on the final leg of their journey home to the House of Grimm. Stumbling upon a coven of witches in a ruined church, they flee for their lives and take refuge in a deserted tavern. Befriended by an amorous yokel, they awake to discover their horses stolen.
Left to cross the wild hills by foot, they are overtaken by a storm and are forced to take refuge in a ditch with a tinker whose tales about the Beast of the Moor make their night sleepless. Reaching Grimm Manor the following day, they are reacquainted with their estranged relatives – great aunt Augusta (Lady Grimm), second cousin Leopold, first cousin Wilberforce, and step-sister Evangelista.