Guest star Paul Burke plays a dedicated research scientist whose vital work on a new drug is threatened when he receives anonymous letters.

Gannon tries to save a 16-year-old girl from heroin addiction. His efforts are continually frustrated by her father, a professor who refuses to acknowledge the problem

Bradford Dillman guests as a methodical police inspector who is accumulating evidence that points to Gannon's protege, resident Carl Webson, as the psychopath responsible for the murder of a young woman.