I hadn't seen this film in years and had actually forgotten how enjoyable it really is.
A young woman, Irma Zimmer (Mabel Karr) seeks revenge after her father dies trying to convince the medical doctors he used to work with that his experiments are a success.
Irma sets out to kill all of the doctors who spurned her father and to accomplish this she uses a weird machine that can make the victim completely obey a "master". She then finds a very attractive dancer with extremely long fingernails whom she brainwashes and uses as an instrument of revenge.
The early Franco films were among his best in my opinion and this is definitely one of them. Some of the images in this film one never forgets including such things as Irma's fake "suicide" that results in her burning her face and then with Irma training her tool of revenge, a dancer named Nadia (Estella Blain)with a whip and chair just like an animal.
Blain pulls off the role of Nadia very well and it's easy to see why the men she kills easily fall for her. She is simply stunning. Franco himself appears as a police officer investigating the strange deaths.
A Highly Recommended blend of sci-fi, horror and mystery.