Caught under the tyrannical thumb of her new prioress, Dame Frevisse finds welcome relief in leaving St. Frideswide nunnery on pilgrimage. But the road brings with it unwelcome company: The wealthy Lionel Knyvet has been possessed by a foul demon. Seeking relief from the horrific terrors visited upon his body each fortnight, Lionel has dragged his entire household on an endless pilgrimage across the breadth and length of England. Frevisse wants nothing more than the peaceful bliss of travel, but must instead endure the incessant chattering of a mob.