This arty Mexican horror happening is a melange of elements from oft-adapted classic gothic stories (Stoker’s Dracula, LeFanu’s Carmilla and de Sade’s Justine) and then-current exploitation cycles (lesbian vampires, possessed nuns and ranting exorcisms).
In 1865, in some European backwater, a relationship springs up between innocent orphan Justine (Susana Kamini) and abandoned-at-birth Alucarda (Tina Romero), a gurning, black-clad witch. At the tomb of Lucy Westenra, Alucarda nags Justine to swear eternal love. A hunchbacked mountebank (Claudio Brook) intervenes to draw them into a Satanic ceremony of knife-cuts on breasts and exchanged licks of blood. The girls go from giggling at the back of class to defying their nun teacher and pledging allegiance to Satan in the schoolroom, which brings down the wrath of the order upon them.
It’s an unusual film convent, with nuns who wear what seem to be white robes stained red by flagellation and menstrual bleeding. The ritual of exorcism presided over by stern Father Lazaro (David Silva) is a sadistic affair which prefigures the ritual abuse of Peter Greenaway’s Baby of Macon as the girls are tied to X-shaped crosses and Justine is stripped and pricked with needles until she dies. A rational doctor (Brook in a second role) intervenes, appalled, and rescues Alucarda, but changes his tune when Justine arises from the dead – emerging naked from a LeFanu-style coffin/bath of blood to attack nuns – and has to rescue his blind daughter from the witch.

