The Reagon family is a famous police family in New York City. Several generations of the family have worked in law enforcement, and some have even sacrificed their lives. Frank Reagon (Tom Selleck) is the current Commissioner of the New York City Police Department and the "head" of the Reagon family. When his father Henry (Len Cariou) was the Commissioner, he got into a lot of trouble because of "mishandling" politics - but this old police officer is very stubborn and has no regrets about anything he has done. Now "the son pays for the father's debt". While managing a large police force, Frank has to constantly make up for the "hard-to-solve" problems left by his father.