The ladies may recognize Nathan Fillion from Desperate Housewives as Dr. Adam Mayfair, husband of Dana Delany's character Katherine, or the lovably adulterous doctor in Waitress. Sci-fi fans of course know him as Captain Mal Reynolds from Firelfy and Serenity. Castle may be the best of both worlds, a hard boiled detective for the guys and a ladies man for the gals.

"A lot of times, actors fall into a trap where they see in a script that a guy is supposed to be really charming and they think sleazy," Fillion said. "That's not what charming is. Charming is, 'I'm interesting and interested,' more so the later. They're not there to bug you. They're not contentious, in any way. You don't feel that you have to fear them. You don't feel like they're too much. They're just happy and glad to be there. That's charming and that's Castle."

Richard Castle (Fillion) is a mystery author who gets a chance to solve real crimes with a detective (Stana Katic) who's not so amused by him. "He's having a good time, all the time. People are attracted to a good time, and that's what Castle has, in spades. He's not a pick-up line guy. He's just honest and in the moment. That's his strength. He says whatever occurs to him. He doesn't have a filter that says, 'Maybe I ought not to say that.' He's just honest and frank."

Castle - © American Broadcasting Companies, Inc.

As a celebrated author in the world of the show, Castle has also become quite media savvy. That comes from Fillion's own deft handling of the press. "Certainly, I know what it's like to be up in front of a bunch of people and talk to them and do panels. It's old hat. It's on my resume now. It's a piece of cake for a guy like Castle, and it's a piece of cake for a guy like me."

If you still don't believe Nathan Fillion is a big star, check out his perks. "I don't have to wait in line at the DMV. That's a big thing."

Castle premieres Tuesday night on ABC.

Story/Interview by Fred Topel

Starpulse contributing writer

(Starpulse in Hollywood): Every week, Hollywood's biggest stars are meeting in the hot spots and Starpulse is there.