Karen Lawson is on the edge of her nerves. She fears that she might be schizophrenic and a recent string of murders in her neighborhood has made her paranoid to boot. Her only comfort is her sister Kate with whom she talks to over the phone. Police lieutenant Trevor Reed and young sergeant Jim Sweeney talk to her about the murders. Later that day, hulking electrician Jimmy arrives to fix the malfunctioning lights in her dance club. Karen shows up and apparently tries to seduce him only to become terrified by him moments later. Jimmy doesn't appreciate this inexplicable change of heart and becomes violent. Meanwhile, Reed, who's also interested in Karen, goes to check up on her as well as check her up. What follows is Karen's deadly descent into madness. But is she really mad or is there another more sinister explanation behind both her sudden mood swings and the killings?