'Castle': Nathan Fillion discusses the finale, season two prospects

ABC will bring the first season of "Castle" to a close Monday night, and series star Nathan Fillion says the prospects for a second season are looking pretty good at the moment.

"The reaction we've been getting from the network is super positive, and the reaction from the audience has been positive," Fillion said in an interview Friday. "That's the most important thing."

Fillion and the rest of the "Castle" cast and crew will find out if the show (one of the favorites in Zap2it's bubble-show poll) will be back on May 19, when ABC announces its lineup for next season. The numbers have been working in the show's favor, though -- its audience has grown in each of the past three weeks, hitting 10 million viewers last week.

Here's what Fillion had to say about working on the show, what to expect in the finale and the chemistry he has with co-star Stana Katic, who plays Kate Beckett, the NYPD detective who reluctantly chaperones Fillion's mystery novelist, Rick Castle, on her cases.

What's the experience been like working on "Castle" this season?
Really nice, really interesting. It's always a pleasure when you go to work and you're working for a bunch of people who enjoy telling stories. [Creator] Andrew Marlowe, he's obviously good at it, but he has a real love for it. ... [Executive producers] Rob Bowman, Laurie Zaks, Armyan Bernstein -- these are names you might not know unless you study the credits ... but they're names that mean a lot to me because I'm working for these people, and they're pulling all the strings and making everything happen smoothly for me. So this has been a really pleasurable experience, and I'm getting to play a character that entertains me.

How does he entertain you?
He has all these negative qualities -- he's immature, selfish, self-serving. He has all these unforgivable qualities, and yet you forgive him. He's not negative, he's very, very positive, he's not trying to hurt anybody's feelings, he's having a great time. There's some sort of filter that he lacks. So when he does these unforgivable things, he does it in such a way that it's not negative, he's not kicking or hurting anybody. He's just being him. And you forgive him.

But he seems to know where certain lines are. He's clearly a pretty good father and at least a tolerant son.
I think everything has its rightful place in his life. As crazy as his mother drives him, and we all have mothers that drive us crazy, he still loves her. He's not going to be unloving to his mother. As silly and immature as he is with his own life, he cares very, very deeply for his daughter and only wants to protect her. It's not about, that's how he's learned how to be. It's something in his heart that drives him.

What can you tell me about the finale?
I don't want to tell you much -- it's so lovely. I wish I would've prepared something beforehand or talked to Andrew, who's so much better at this. [Per ABC, the case of the week is the murder of a plastic surgeon, while Castle digs around in Beckett's past a little too aggressively.] But I'll tell you this -- this is an episode where we see just how clever or appropriate Castle can be when it comes to where you draw the line, and how far you go before it's too far.

Is it self-contained, or is there some potential setup for next season?
Certainly being a season finale, we're going to have a nice little cliffhanger for everyone. It's worthy of biting nails.

The chemistry between you and Stana Katic seems pretty strong. Is that something you can work at, or does it just sort of happen?
One of the reasons I love "Castle" is that it's a very collaborative effort. If someone has an idea to make a scene better, all they do is say, "Hey, you know what would make this scene better is ..." and then we practice it. It's such a compressed environment -- we don't have weeks of rehearsal. We only have a couple minutes before digging in and doing it, but just that process of rehearsing -- even the process of during filming, there's life in it that can be discovered. If it makes it more natural and makes it more real, that's what we're going for.

But is it also just something that's there with you and her?
I've said this before -- Stana can act chemistry with a wet paper bag. And I'll be playing your wet paper bag.

Do you feel like Castle has gotten a little more in tune with how Beckett works, that maybe he's not only interested in a good story?
I think now he's finding out that murder matters. As uninvolved as he [has been] with the plight of the victim, he's seeing now when he meets victims' families that murder does matter to someone. When we had the episode "Hedge Fund Homeboys" [the season's third], that really drove it home for Castle. Because now it's a teenager who's dead, and he's invested that was because he's got a teenage daughter. I think he's seeing where murder does matter, however he's -- again, his angle of attack is completely different from what a police officer might think. He's a guy who tries to think outside the box. He's not constrained by procedure in any way. I think also the police department has come to respect his talent for at least thinking outside the box the way he does.

Do you foresee somehwere down the road that he'll actually finish the book with Kate's character as the star?
I think not only will he finish that book, but I think it will be the birth of a new series. The way he had the Derek Storm series, I think Kate will be honored in much the same way.

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