In Herefordshire's hop-growing country, where the river flows as dark as beer, a converted kiln is the scene of a savage murder. When the local vicar refuses to help its new owners cope with the aftermath, diocesan exorcist Merrily Watkins is sent in by the Bishop. Already involved in the case of a schoolgirl whose deeply-religious mother thinks she's possessed by evil, the hesitant Merrily is drawn into a deadly tangle of deceit, corruption and sexual menace as she uncovers the secrets of a village with a past as twisted as the hop-bines that once enclosed it.