INQUISITION

In medieval France, the plague is spreading across the countryside, and the ignorant peasants believe it to be the work of witches. Bernard de Fossey, the local "witchfinder", travels from town to town on a holy mission, aided by his two lecherous assistants Nicolas Rodier and Pierre Burgot, rooting out witches and executing them.

Most of the women deny they are witches, but Fossey and his men torture them sadistically until they confess, at which point they are executed.

Catherine, a beautiful young girl in the village, is in love with Jean Duprat, who wants to marry her. Fossey develops a crush on Catherine unfortunately, and hires some highwaymen to rob and kill Jean in the forest. That night, Catherine has a dream in which she sees the killers being paid with coins to murder Jean, but she can't see the face of the ringleader.

Catherine makes a pact with Satan, agreeing to sell her soul to him if he will help her to avenge the death of her fiancé. She drifts into some bizarre dream sequences wherein she meets Satan (played by Paul Naschy in a leotard) and the red-eyed demon Belphegor, who eventually tell her that it was Fossey who paid for the killing of Jean Duprat.

Catherine seduces Fossey and slyly involves him in some immoral activities that wind up getting Fossey himself accused of witchcraft and the witchfinders torture him, shave his head and sentence him to death, along with Catherine. Naschy wore a full skullcap for the finale of the film. Catherine sacrifices her own life to insure that Fossey also pays for his crimes, as both of them are burned together at the stake in a fiery scene reminiscent of Ken Russell's 1971 film The Devils.

Catherine sacrifices herself to ensure that Bernard de Fossey is also accused and executed; both are burned at the stake together.

The ending brings Naschy’s grim vision full circle: the witchfinder falls victim to the same fanatical machinery he once wielded, and Catherine’s pact with Satan secures poetic, if brutal, justice. It’s a bleak commentary on cycles of cruelty and the perverse logic of hysteria, leaving no one unscathed by the flames of superstition.