I think he will not retire, but, he'll seriously consider it. I think the season finale should have a last 15 minutes of a look into the future. Jamie has Chief of Patrol, Danny as a lieutenant in charge of a squad. Erin as DA of Manhattan. Eddie as a detective sergeant, and the mother of 2kids. Frank sitting at the dinner table alone, waiting for the rest of the family to arrive for dinner, and fondly ing his father, then the whole family shows up and it's Sunday dinner as usual, with Frank talking about how proud he is of all his kids and grandkids.