Lucita (Jenny Tamburi) has been sent to the convent after she fell in love with an excommunicated heretic, Esteban (Paolo Malco). Hunted down by the Inquisition, a wounded Esteban makes his way to the convent where he seeks Lucita. Hidden by a benign stable-hand, Esteben convalesces while scheming to rescue Lucita from a nun's existence. Lucita is able to help Esteban heal, however, her room mate Josefa (Bruna Beani) learns her secret. Josefa blackmails Lucita claiming she will not tell the Abbess (Francoise Prevost). Josefa demands that Lucita have a lot of lesbian sex with her as payment for not ratting to the Abbess. Lucita agrees and they get right down to it. Uh oh....Josefa is stabbed to death shortly after the blackmail, and Lucita is accused. Now Lucita is a prisoner in the convent sentenced to death by Father Onorio (Corrado Gaipa). Now Esteban must rescue his love.
Now...you gals out there take note. If your main squeeze really loved you, he would be prepared to do what Esteban does in hopes of saving Lucita. Esteban seduces the Abbess (head nun) and has a night of wild sex with her...in hopes of her agreeing to assist in freeing Lucita. Like most pre-marital sex, the consequences of this wild night are horrific. No spoilers here, but what follows is madness, murder, and heresy. As we will now find out, lesbian orgies are routine at this convent...and so is murder. Unfortunately for Esteban, the Abbess is actually a black widow type figure, seducing men, killing them, and depositing them in a mass grave. Can Esteban rescue Lucita? Is the fact that both our lovers had wild sex with nuns an indication they are a perfect match? Do nuns really look like the babes in this film?
The ending of this film is shocking. The fate of this convent is right out of an Edgar Allan Poe story. The eroticism present in 1970s Italian horror is present in "The Sinful Nuns of St. Valentine" in full force. Available on Netflix, not for the whole family (...which is the way we like it), see this 1970s Italian classic.