Mr Luparello, a renowned local engineer and leading political figure, is found dead in a car at a notorious prostitution spot on the outskirts of Vigata. The coroner rules that he died of a heart attack following an amorous encounter. Fending off pressure from prominent ecclesiastical figures who wish to keep the case under wraps and navigating the intricacies of local party politics, Montalbano goes about making sense of the available evidence, including the incongruous discovery of an expensive necklace found at the site of the murder.