Caitlyn is enjoying her first autumn in England, nut-picking in the forest, creating delicious treats in her grandmother's enchanted chocolate shop, and dreaming of cosy evenings with the handsome Lord James Fitzroy. But the peaceful atmosphere shifts when a mysterious woman claiming to be a witch arrives in the village. Some love her, others are wary... and one person might have more dangerous intentions.

Soon Caitlyn finds herself drawn into a mystery with links to ancient folklore and—with the help of her toothless vampire uncle and a few chocolate spells of her own—she sets out to do some magical sleuthing. But strange and puzzling incidents keep happening, leaving her worried and confused. Why isn't her kitten Nibs growing any larger? What does the new guest at Huntingdon Manor really want? And what is the jewel that seems to be exerting an unusual influence over her cousin Pomona?

Troubling events are stirring in the village of Tillyhenge, and Caitlyn is about to discover that old suspicions about witches run deeper than she imagined...