S1, E14: Starsky and Hutch help an old buddy who says he wants to locate his son by a former marriage. The detectives do not know their friend has become a professional "hit man" and that his alleged ex-wife's present husband, a reformed crime syndicate figure, will be murdered if their quest is completed in "The Deadly Imposter." John Colby, with whom Starsky and Hutch were close friends at the Police Academy, shows up after an absence of five years, claiming he was a prisoner in North Vietnam and later spent two years in a Hawaiian hospital. Now, all he wants is a visit with his young son, whose mother found a new life after divorcing him. What Starsky and Hutch do not know is that Colby was never married, has never fathered a child and is actually a pro-fessional killer with a "contract" to execute an ex-syndicate accountant named Warren Karpel.