Blue Bloods returns on Friday, October 7. With a run for DA, Erin is poised to join her dad, the police commissioner, as a leader in law and order.

Here, New York City’s top cop and Reagan patriarch Tom Selleck gives an inside look at Season 13.

In the premiere, Frank goes on an incognito late-night walk around the city to check on his cops. What’s the result?

Tom Selleck: It gives him insight into the loss of morale in the NYPD, and he’ll deal directly with that serious issue. Frank has had to walk a tightrope in this woke environment. Now he’s realizing he’s not going to be as diplomatic, and I like that for him. He’s due for a confrontation with Mayor Chase [Dylan Walsh] — ’cause he seems to be talking out of both sides of his mouth, in Frank’s opinion.

Blue Bloods has always strived to be nonpartisan.

It’s a show about a law-enforcement family and their point of view, but it doesn’t mean they’re always right and their adversaries don’t have a point…unless they’re just flat-out murdering criminals. [Chuckles]

Will Frank go out on a limb and endorse Erin for Manhattan DA?

He wrestles with that. Is his endorsement a plus or a minus? It gets intense for the whole family.

Can we look forward to some interesting guests at Sunday dinner? Returning grandkids? Erin’s ex-husband, Jack Boyle (Peter Hermann)?

I won’t say who, but you’ll be surprised how many people are at the table. And Jack’s been lurking.

Bridget says making it to 15 seasons would be lovely. You in?

I’ve got a mortgage. I’m game!