The Demons on AllMovie

Jesus Franco, Spanish cinema's leading purveyor of the perverse, sank to an all-time low with this lecherous and sadistic tale of torture, debauchery, and demonic possession. Taking a cue from Ken Russell's far superior The Devils, the vile deeds take place within the walls of a Medieval convent. The story begins with a powerful sorceress being burned at the stake by agents of the Inquisition; before the flames consume her, she manages to spit a curse upon the descendants of principal witch-hunter Lord Jeffries (John Foster) and his underlings. Decades later, the witch's twin daughters -- both nuns in a cloistered abbey -- are overcome by their mother's vengeful spirit. This leads to another round of sadism as the sisters are accused of witchcraft themselves and subjected to a gallery of vile tortures while Franco's camera lingers lovingly on every depraved act of sex and violence. Justice is finally served (more or less) when one of the sisters develops the ability to vaporize people by kissing them. This is achieved via sloppy special effects -- another Franco trademark.