Stanley G. Weinbaum’s short story “The Adaptive Ultimate” starred Zachary Scott and Peter Hensen when it was adapted as an episode of SCIENCE FICTION THEATER, Richard Derr and Lola Albright as a TALES OF TOMORROW, and Richard Hart as a STUDIO ONE. So it was already a well-worn tale on television when Carroll Young (JUNGLE JIM) and Kurt Neumann (THE FLY) adapted it for Regal. Dr. Scott believes he has created a serum that can cure all diseases, punctures, broken bones, and other ailments. He wants to test it on humans, but Dr. Bach isn’t sure that’s ethical.
However, one patient, Kyra Zelas (Mari Blanchard), a terminal tuberculosis patient with no family, friends, or income, interests Bach, and he okays the injection of Scott’s serum. It works. She’s up and walking around Beverly Hills in no time, and the two doctors invite her to move in with them and Hannah. They don’t yet realize Kyra has also changed into a stone cold killer who can mentally change the color of her hair (director of photography Karl Struss achieves this without cutting or visual effects by using lens filters).
The worst of Neumann’s four science fiction films as a director, SHE DEVIL basically just plods along with Kyra vamping the men around her to get all the nice things she’s always dreamed of and poor lovesick sap Scott falling for her. It isn’t the fault of Blanchard (ABBOTT & COSTELLO GO TO MARS), who looks smashing as a blonde and acts believably as a murderous trollop. It’s merely that the story’s stakes aren’t high enough. Kyra is dangerous, but she isn’t that dangerous. Bach and Scott don’t even kick her out of the house, and Scott remains in love with her even after she has killed two people.
Plus, SHE DEVIL is just sloppy. Neumann expects the audience to believe that just changing her hair color makes Kyra unrecognizable to others. When she forces her new husband (John Archer) to drive over a cliff, Neumann cuts to a stock shot of a car backing over the cliff. Blanchard made a few more movies and plenty of television episodes before dying of cancer in her 40s.