A couple of detectives investigate stalkers . Powerful and concentrated, Lt. Beth Davis is also an expert in the specialty of repeated harassment, driven by personal experience to be a victim. She heads the Threat Assessment Unit, which investigates examples of stalking -- including voyeurism, cyber-harassment and fixation of the LAPD. Recent transfer Jack Larsen's foundation -- whose personality and also questionable behavior have now already been a problem in the past -- may help him into his mission for her team. Her other detectives are Ben Caldwell and Janice Lawrence. Together they attempt to maintain their obsessions -- and to stop situations from spinning out of control.