Night of the Scorpion (1972)

An archeologist's wife has recurring nightmares about ritual killings in an Etruscan tomb while her husband is away excavating a lost temple. After a phone call where she is forced to listen to him being murdered, she travels to the excavation site to solve the mystery of his death.

The 1800s: scholarly Karl Schiller believes he's found the ring of the Nibelungen, which holds great power. It's at Castle Dracula. His twin, Franz, a gambler, asks if vampires frighten Karl; Karl shows him an Egyptian amulet, which may protect him. Franz takes the amulet and sets out ahead of his brother, arriving at the castle first. There he finds a countess who invites him to dine. Later that night, Karl arrives. Coincidently, it's the Night of the Virgin Moon, a night that falls every fifty years and draws five virgins from the surrounding village to the castle not be heard from again. Can Karl protect his brother, find the ring, and rescue any of the women?

A blind pianist tries to figure out who is responsible for a string of murders using a black cat with its claws dipped in curare.