In the wake of a series of unfortunate experiences in the Cotswolds, Thea Osborne, accompanied by her spaniel Hepzibah, is perhaps over-optimistic about the English summertime and the possibilities of her latest house-sitting assignment in the secluded village of Cranham.

Despite the ease with which Thea's new job begins, looking after Harriet Young's reptiles, she soon finds a dark side to the characters she encounters. From the elderly Donny Davis to the enigmatic figure of Edwina, it soon becomes clear Harriet's beloved geckoes are not the only cold-blooded creatures at large in Cranham...