Description from Mondo Digital

In the 1800s, young orphan Justine (Susana Kamini) arrives at a repressive convent where Alucarda (Tina Romero) has spent her life since infancy. They become fast friends and, while frolicking in the woods, encounter a sinister gypsy (Claudio Brook) who warns them about a nearby cemetery, the devil's stomping ground. After unleashing a malevolent power inside one of the tombs, Alucarda proves to be the most susceptible upon returning to the convent. The gypsy then magically reappears and initiates the girls into the ways of the horned one, courtesy of a blood rite and a sylvan orgy. Potentially bisexual Sister Angelica (Tina French) realizes something's amiss and decides to stage an exorcism, though the ceremony of tying the girls naked to crosses proves to have disastrous results. The local physician, Dr. Oszek (also Brook), finds himself unable to explain away the bizarre deeds occurring within the convent walls, which escalate when Justine seems to be killed... or does she?

A long way from those K. Gordon Murray Mexican horrors for the kiddies, Alucarda is one of the more striking and shocking south of the border gothic fests from the golden age of cinematic sleaze. Replete with nuns, devil worship, blood baths, and sadistic religious fanaticism, this is one drive-in jewel ripe for rediscovery.