Tri Jekyllin paluu was released in the year 1971。Tri Jekyllin paluu is also called as Dr Jekyll & Sister Hyde, Médico & Irmã Monstro, Dr. Jekyll og søster Hyde, Dr. Jekyll och syster Hyde, Dr. Jeckyll et sister Hyde, Barbara il mostro di Londra。

Dr. Henry Jekyll, in attempting to find a toxin that will wipe out all common diseases, accidentally stumbles upon a formula that transforms him into a gorgeous but evil woman. He needs female hormones for his experiments, so a number of London women meet bloody deaths.