Count Dracula's Great Love

In this 1973 Spanish film, a group of four women and one man seeking refuge in an isolated sanitorium fall prey to an evil doctor who harbors a terrifying secret. As the night wears on, they succumb to his sinister plans, leading to a descent into torture, lesbian sex, and bloodshed. Ultimately, only one woman remains uncorrupted by the doctor's dark powers, but will she be able to escape the clutches of Count Dracula?