Based on a novel by John Brophy, Turn the Key Softly takes place within a single day. The film follows the exploits of three newly released female convicts. Monica (Yvonne Mitchell) is full of hatred for the man who led her into a life of crime. Stella (Joan Collins) is an impulsive streetwalker who is determined not to return to her old lifestyle. And Mrs. Quillam (Kathleen Harrison), an elderly shoplifter, misses out on her chance to start anew in a most ironic fashion. Slightly hoked up with a rooftop chase, Turn the Key Softly is an otherwise straightforward psychological drama.