The new captain of the Carabinieri, Fabio Leopardi, arrives in a quiet provincial town, called to investigate the possible existence of a satanic sect which has led to the death of three people: the parish priest of the town, who died in an alleged accident, the captain of the carabinieri, apparently dead by suicide, who was investigating the death of the priest, and a young student, found dead in a ditch, who behind her 'good girl' appearance hid the use of narcotic substances and the practice of rituals satanic. Despite a series of misdirections, Leopardi will be able to shed light on the case.