For Jenny, already upset with her mother's remarriage, the move, and the state of the house, the final straw comes when Mister Cat must be quarantined for six months.

Following the cats one night, Jenny locates the mysterious third-story room, where she discovers the ghost of 19-year-old Tamsin Willoughby, daughter of the farm's original owner.

Ghosts endure as long as they remember being alive, but Tamsin has blocked out the circumstances surrounding her death, including what became of her sweetheart Edric Davies.

Jenny and Tamsin become close friends, and Tamsin introduces Jenny to the numerous supernatural creatures that occupy the grounds, including the shape-shifting Pooka, while teaching her to avoid more dangerous beings such as the redcaps who occupy the nearby forest and the all-powerful Old Lady of the Elder Tree, who ruled the land before mankind came.

Jeffreys used the power of Tamsin's dying words to summon the Wild Hunt to chase Edric for all eternity, resulting in the screams heard on stormy nights.

Only Tamsin is capable of undoing the curse and freeing both herself and Edric, but she is slowly succumbing to Jeffreys' more powerful and determined spirit.