The team is assigned to watch over a Crown Prince on a one night stay in San Francisco. With Eve accompanying him on an unscheduled tour, and Ed following along behind, it seems that he is safe from harm; or is he?

Ironside attends a hospital for psychological evaluation, and whilst he is tying knots in his psychiatrist's theories, it transpires that a crook is trying to use the situation to find out the whereabouts of a police informer. With Mark and Eve on holiday, however, there is just Ed to help the Chief, and a whole city to search through for clues.