Frightmare

After escaping a death sentence for her hideous crimes, a seemingly rehabilitated woman settles in an isolated farmhouse with her husband, only to ache, once more, for blood, and a crash-course in surgery. Is, indeed, her old self back?

Frightmare is a 1975 horror movie directed by Pete Walker, starring Rupert Davies, Deborah Fairfax, Paul Greenwood. It holds an IMDb rating of 6.2/10 from 3,001 votes and runs 1h 28m.