The rich but lonely Doriana Grey (Lina Romay) lives in an old castle together with her servant Ziros. An American reporter (Monica Swinn) visits her to write an article which might also help Doriana uncover a mysterious secret buried in her past. The secret turns out to be a twin sister who is hidden in a psychiatric hospital, run by the mysterious Dr. Orloff. Born as Siamese twins but separated after birth, Doriana suffered some sort of sexual trauma, while her sister’s became mentally defective. Doriana is a frigid sex vampire, telepathically connected to her twin sister who actually experiences the orgasms which elude Doriana. Ziros supplies Doriana with victims. Drawn to their sexual activity, Doriana appears to suck the life force out of her victim’s genitalia in search of the ultimate sexual climax. Doriana finally sees only one solution to her suffering. She visits her twin sister to make love to her and suck out her vitality and sexual power…