Olivia's home is the Green Man Inn, situated in medieval city of London. She is content with her life, running the bustling tavern with her father, and is taken aback when he suggests a long journey in late autumn into the west of the country to meet her mysterious bridegroom.

As Olivia gets farther away from the busy metropolis, her concerns grow, especially as Halloween approaches. She senses something strange and unearthly in her fate, and her imagination conjures up fearful images.

All alone in the wild forests of Wales, will she be an unwilling sacrifice to the pagan gods?