Steve Granitz/Wire Image/Getty Images Tom Selleck

The Magnum P.I. floral shirt is gone, but Tom Selleck and his famous mustache make their return to prime time Sept. 24. Selleck plays New York City police commissioner Frank Reagan, patriarch of a multigenerational police family, in Blue Bloods on CBS. He spoke to Time about cops, mustaches and a Hawaiian shirt comeback.

Do the Reagan kids have to go into the family business or do they sort of fall in?

No, my character lost a son in the line of duty. Another son, the oldest, is Donnie Wahlberg's character. The youngest son (Will Estes) was a Harvard graduate and a lawyer who gives that all up to become a rookie cop. (See the 100 best TV shows of all time.)

It sounds a lot like The Godfather with him as the Al Pacino character.

It's The Godfather of law-abiders.

Was there ever a discussion about not having the mustache for the show?

I always get mustache questions, that is so weird.

Well, you've got a great 'stache.

Thank you for that. I guess it's a great 'stache. But I was born without it. The show won't, I guarantee, be about my mustache. That's a promise.

I always think of you with it, can't think of a role you didn't have it.

In & Out. Ike: Countdown to D-Day. It would have been a bit of a lie to play Eisenhower with it. It happens quite a lot.

How long does it take you to get it back in full form?

It's probably workable in three weeks but it isn't in full flower until a little beyond that. It comes back  I'm still pumping some testosterone  but it takes time. (See pictures of the world beard and moustache championships.)

When Jimmy Fallon called you out on the Emmy stage as his long-lost father, were you thinking paternity suit?

No I wasn't! But I was very surprised. i was standing in the wings before I went on and I couldn't hear him so i didn't even know what he said when I came out. Then this guy in this white dinner jacket hugs me. So it was pretty funny. i had no idea that anything was planned. He hugged me and I was surprised but I just kind of went with it.

Congrats on getting into the Cowboy Hall of Fame. Who are you next to in cowboy eternity?

I have no idea. At the induction, they had a special spot. I'll fit in there somewhere. It would be nice to be near John Wayne. That's as close as I'm gonna get to him.

What will happen with your California avocado farm while you are doing the show? Will it affect the nation's strategic guacamole supply during football season?

Well guacamole is for the rejects. I hate to tell you. Your lowest price is guacamole-level avocados. A good crop stands on its own on the shelves as its own piece of fruit. But there will be plenty of guacamole because there are plenty of rejects because of the draught.

How's the livestock on the ranch?

We're moving away from livestock. Billie and Lillie are gone  the sheep. Gertie and Bertie are cows and they are gone. We have four horses. And we're down to four dogs. And I just put a turtle in the pond. If he or she makes it and gets big I'll probably name it. Having this discussion makes me think even if it's a guy I'm going to give it a woman's name.

I like Gladys then.

That is a good name. Any name that needs bringing back.

I'll push Gladys since I want to name Tom Selleck's turtle.

Thelma, Gladys or Nelly. But Gladys is right up there.

I have to ask you about the Magnum, P.I. movie.

I know nothing. They haven't asked. They wanted to do one in the '90s. Tom Clancy wanted to write it because he was a big Magnum fan. But they blew it. It would be fun to revisit the guy. The problem with movies about television is they usually spend $100 million on explosions and then make fun of the original show. I'd hate to see that. The fans wouldn't like it.

Could anyone else play you?

I really don't want anyone else to play me. But would I play me, and they were weren't writing Magnum as a 17-year-old? I'd probably take it on.

Where's Magnum now?

I know where he is. He went to being a Navy seal. If they do a movie, they should do it when he gets out of the Navy and tries to back to his life in Hawaii.

Will there be any need for Hawaiian shirts in Blue Bloods?

Not for my character. Besides, my Hawaiian shirt is in the Smithsonian.

You could get a copy.

No, I won't.

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