In the wake of a series of unfortunate house-sitting experiences in the Cotswolds, Thea Osborne, accompanied by her spaniel Hepzibah, is perhaps optimistic about the English summertime and the possibilities of her latest assignment-house-sitting for transatlantic reptile breeder Harriet Young. Despite the ease with which Thea's new assignment in the secluded village of Cranham begins, she soon finds a dark side to the characters she encounters. From the elderly Donny Davis to the enigmatic Edwina, Thea begins to realise that Harriet Young's beloved geckoes are not the only cold-blooded creatures at large in Cranham.