Mari Blanchard as Kyra Zelas
Jack Kelly as Dr. Dan Scott
Albert Dekker as Dr. Richard Bach
John Archer as Barton Kendall
Fay Baker as Evelyn Kendall
Blossom Rock as Hannah, the housekeeper
Paul Cavanagh as Sugar Daddy
George Baxter as Store Manager
Helen Jay as Blond Nurse
Joan Bradshaw as Redhead
X Brands as First Doctor
Tod Griffin as Intern
She Devil is a 1957 American science fiction horror film directed by Kurt Neumann, and starring Mari Blanchard, Jack Kelly and Albert Dekker.
Dr. Dan Scott has developed a serum that cures the ills of animals, although it did alter the color of a leopard used in one experiment. Eager to try it on a human being, despite his mentor Dr. Richard Bach's many concerns, Scott finds a consenting patient in Kyra Zelas, a woman with a meek personality who is dying of tuberculosis.
The serum seems to cure her instantly. It also dramatically affects her personality, Kyra shows a flash of temper, then jumps out of a car and runs into a shop, where she steals a dress and disguises her identity by willing her hair color to change from brunette to blonde.
Scott falls in love with her. At a party, however, Kyra seduces a guest, Barton Kendall, and when his wife Evelyn objects, Kyra disguises herself again and murders her. Then she marries Kendall, but behaves monstrously toward him. The doctors use a ploy that leaves Kyra in an unconscious state, then perform surgery to reverse the serum's effect, which also restores Kyra's terminal disease.
Film critic Glenn Erickson discussed the production in his review of the film, "The B&W 'Regalscope' format gives this modest production a handsome look, along with Kurt Neumann's competent if not stylish direction. Cameraman Karl Struss (of Murnau's Sunrise) slightly over-lights Kyra in the party scene to make her hair seem to glow, a subtle effect for sure. The hair-color changing is a filter trick, an invention Struss first used back in the silent era. A spectacular car crash murder scene is an RKO stock shot lifted from the 1952 Otto Preminger noir Angel Face and cropped for the 'scope format. It still looks frightening. Suggesting an undeveloped noir angle, a 'haunting' portrait of Kyra becomes the focus of Dan's obsession. It's supposed to be the work of an Italian master, but looks more like a Paint By Numbers atrocity."