In the small Southern Italian village of Accendura, three local boys, Bruno, Michele, and Tonino are engaged in mischief and other activities. Guiseppe Barra (Vito Passeri) a local simpleton and peeping tom, who is seen spying on two rowdy swinging couples, is surprised when which the three boys appear behind him and yell out, "Giuseppe's a big baby!" which goads him into a state of bitter resentment.Meanwhile, in the hills surrounding the village, a reclusive Gypsy witch named La Magiara (Florinda Bolkan), is conducting sinister black magic ceremonies, first by digging up the skeletal remains of an infant, and then plunging pins through the heads of three tiny clay dolls. It makes it clear that these are the three youths taunting Giuseppe.When Michele returns home, his housekeeper mother urges him to deliver some orange juice to their employer, Patrizia (Barbara Bouchet) a young woman from Milan who is laying low in the village after a drug scandal. It becomes apparent that Patrizia offers undefined sexual favors to the local adolescents when she's shown sexually taunting Michele.When Bruno Lo Casio goes missing, a media circus begins as reporters from all over Italy converge on the town. One of them is Andrea Martelli (Tomas Milian) a sharp-witted journalist from Rome whose insights into the case are acknowledged by the regional police commissioner (Virginio Gazzolo) working with the collaboration of the village chief of police Captain Modesti (Ugo D'Alessio). Amid local hysteria, Giuseppe is soon arrested when he's found near the dead body of Bruno. But he protests his innocence for he claims to have only discovered the body of the boy and then phoned the parents in a feeble attempt to extract a pitiful ransom of six million lira. When another dead body of a young boy, that of Tonino is found, the police realize that he really is innocent.A few nights later, during a raging thunderstorm, Michele Spriano, sneaks out of his house to meet with someone he speaks to over the phone, and he too is strangled by an unseen assailant and his body is found the following morning.Martelli soon meets and befriends Patrizia whom he recognizes from newspapers where he used to work in Milan. Patrizia is considered a slut by rest of the insular villagers mainly because of her modern style of dress with halter-tops and mini-skirts. Martelli also meets with the amiable young village priest, Don Alberto Avallone (Marc Poreli) and his strangely reserved mother Aurelia (Irene Papas). Don Alberto runs a boys group at the church (which the murder victims came from) and he also encourages the boys to play soccer on the church grounds to keep them off the streets and out of trouble. Since he is the priest and connected with the powerful Catholic Church (which holds the real power in Italy), he is well known and respected by everyone in the village and surrounding area. But Aurelia is a dour mysterious woman. A villager confides in Martelli that, "she is only tolerated because she is the priest's mother."Elsewhere, Captain Modesti and his aide meet with Francesco (George Wilson), an eccentric old hermit living in a tumbledown stone hut in the hills overlooking the town, who practices black magic and offers charms and potions to the superstitious. He claims to the police that he has passed his knowledge of black magic to his disciple, Magiara, and also shares time with the causal thrill-seeking Patrizia. He is also rumored to have had (and then disposed of) a baby from a tryst with Magiara.Angered by Francesco's unwillingness to co-operate with the investigation, the police proceed to hunt down and arrest Magiara. Under interrogation, the fevered woman gleefully confesses to the murders. However, it transpires to Modesti and the Commissioner that she believes her voodoo dolls and incantations have merely brought about the deaths of the three interfering boys, and she profess to have no interest or awareness of the physical methods used. An alibi provided by a policeman sighting Magiara miles away from the latest murder scene clinchers her legal innocence and she is released the following day.Nonetheless, the hostile and superstitious villagers are not convinced and the so-called "witch" is set upon in a local graveyard by a small mob of men who savagely beat her with heavy chains and then leave her for dead. The bloodied and mortally wounded Magiara drags herself quite a distance to the nearby expressway where she futilely tries to flag down a car, and then dies on the shoulder of the road. The following day, another young boy is found murdered, drowned in a local stream, which further increases police frustration to the case. However, the unsophisticated and religious townspeople are beside themselves with silent fear... continuing to believe that "the witch" is responsible for the killings and she is doing so from beyond the grave with a curse over the whole town.Patrizia herself briefly becomes a suspect when Martelli finds her gold-plated cigarette lighter at the scene of the latest killing and while being interrogated by the police, she refuses to supply an alibi for those nights of each killing. But under the threat of incarnation, she's forced to admit that she traveled outside Accendura to buy marijuana for herself. With little to hold her on, the police let her go as well.Martelli and Patrizia become more determined to track down the killer on their own. During further meetings with Don Alberto, Martelli also learns that Don Alberto's mother has another young child, a six-year-old girl born mentally retarded. Martelli becomes convinced that the little girl is a witness to the killings after seeing that she compulsively pulls the heads off her dolls, as if doing an imitation to the strangulation's. One doll's head, that of Donald Duck, is found near the latest crime scene, which this leap of reason proves accurate. But Martelli and Patrizia wonder: is the killer the priest or his mother?When Aurelia disappears with her daughter, Martelli and Patrizia track her down to a remote shack on a hill overlooking the town and when they arrive, Aurelia is found barely conscious begging them to help her stop her crazy son. It is Don Alberto who is the killer. It turns out that he straggled those young boys not for their sins, but to PREVENT them from committing sin when they grow up, as well as save them from the "horrors of sexuality", thus (in his mind) sending them to heaven with clean souls.In an act contrary to even his sick rationale, he attempts to throw his little sister, a witness to the crimes, off a remote cliff. Martelli arrives in the nick of time, and after a long and climatic fistfight between Martelli and Don Alberto, the twisted priest looses his balance and falls of the cliff to his gruesome death.