Credit: ABC/Richard Cartwright Photo: Beckett Arrives at Castle’s House on Castle Season 5, Episode 19, “The Lives of Others”

Next Monday, April 1, Castle will air its 100th episode, and Wetpaint Entertainment had the pleasure of chatting with the Castle mastermind Andrew Marlowe about that major milestone, his favorite episodes of the series thus far, the uncertain future of Castle and Beckett, and so much more!

Check out Andrew’s thoughts below and be sure to read part one of our exclusive interview with the Castle creator in case you missed it!

Wetpaint Entertainment: Is there pressure in making a milestone episode?

Andrew Marlowe: There's certainly pressure if you allow there to be pressure. We had a bunch of big episodes this spring. We did the episode with Senator Bracken. We did the two‑parter. We have some bigger episodes coming up — and we've also done some personal episodes, one focusing on Esposito, and one that airs before the 100th that focuses a little bit more on the Ryan character. So I decided instead of putting a whole bunch of pressure on the 100th and doing the greatest most awe-inspiring episode anybody has ever seen on television — which will drive you crazy and probably mean that you will not make a very good episode — my desire was to basically deliver the quintessential Castle episode. Something that could have been in any of our Castle seasons that really puts a lens on the Castle/Beckett dynamic and serves as kind of a glass of champagne for our audience. It's bright. It's sparkly. It's fun. It's intriguing, and it allows for great character interaction with all of our primary cast. So we're really excited about it.

Can you say anything about the plot of the 100th?

Well, I think it's out there that there are elements of it that are a bit like Rear Window, and Castle ends up in a position where he's the boy who cried murder where he's seen something across the way but can't get Beckett or Ryan or Esposito to believe him. Initially, of course, they go and check it out, but there's nothing behind it. Castle has broken his knee cap on a ski weekend with Beckett trying to impress her by doing something really stupid on the slopes, and so he's paying for it, and of course, he's going out of his mind because he can't investigate the cases with her. You can't be at crime scenes hobbling around on crutches. So he's frustrated, sitting at home, bored, when he sees something, but that's just the tip of the iceberg of this particular episode.

Should we be looking for homages to Hitchcock?

Oh, yeah, all the way through it, also lots of little nods and winks to the audience where in subtle ways we reference past episodes.

It must be insane to reach a hundred. Not a lot of shows do these days.

That's what I'm told. Yeah, it's a huge milestone. I think when you're making a TV show, you're just concentrating on making the best show that you can every week. And a hundred sneaks up on you. And you think back on the number, and you suddenly think, "Oh, man. I'm really tired."

Or I've killed a hundred people.

Yeah. But, my philosophy has always been, don't look at the top of the mountain, just look at your feet and keep walking, and that's what we've done the last couple seasons, just trying to figure out how to make our shows better, more interesting than the last one, and hopefully the audiences enjoy the ride.

Credit: Nancy Rivera/Splash News Photo: Creator Andrew W. Marlowe and Stana Katic Pose at "An Evening With ABC's Castle" at The Ray Stark Family Theater in Los Angeles on Nov. 4, 2012

We really enjoyed the two‑parter.

Oh, thank you so much. It was a big swing, so we're glad that it paid off, and really happy with Brolin's work and Chris Heyerdahl who played Jacques Henri, the guy who Castle hires. I just thought he did a phenomenal job. We got really lucky with our guest cast in both those episodes. Bernard White who played Anwar El-Masri was phenomenal. We're really pleased with how it turned out, and again, Molly [Quinn], really brought it, showed a different side and showed her maturation as an actress during the hundredth episode celebration that we had down here, I was saying a few words and one of them was that when we got Molly, when we cast her, she was like 14 years old. So I think that she has 250 parents on set. These people who have watched her grow up over the last five years, it's been really remarkable.

Do you have favorite episodes along the way?

I have lots of favorite episodes and for different reasons. We have our fun, whacky episodes, and we have our serious, thrilling episodes. And one of the things I love about this show is that it can accommodate a wide tonal range. One week we can be really serious and deal with characters and their demons, and their back stories and their mythologies, and another episode we can go to a super fun science-fiction convention and deal with a Sci‑Fi murder and have fun with the genre. I think that, for me, the pilot was a really special moment.

Our season finale last year where we finally got Castle and Beckett together was a huge moment for me, but there have been lots and lots of other fun ones along the way and little moments that have always been a really good time between Castle and Beckett. The fans have made little fan videos on YouTube chronicling the evolution of their relationship, and when I look at those, that's when it hits me how much we've done with these two characters. When I think back to our second season, the two‑parter where we blew up Beckett's apartment is a milestone in the Castle/Beckett relationship. That one was a lot of fun.

I really enjoyed our season finale from the second season and enjoy it more actually in retrospect now because we think we're dealing with spies, and it turns out we're dealing with a company that does spy games. But there's this huge spy element in it, and now knowing what we know about Castle's father, I love looking at that one in a new light.

At the time, was that intentional?

Yeah. I'm a super genius. No, I think part of it is, knowing that you gravitate towards a particular genre and knowing that Castle has dealt in that world as a novelist because he was coming out of the Derrick Storm novels. So the character was intrigued by that world, so it made sense to root that in something. I think it really did all come out of the fabric of who Castle's character is. So as opposed to me being super smart, it was more an understanding of the character and then filling out the world in a way that made sense.

I really loved our time travel episode, “Punked,” in Season 3 where the guy was killed with the antique bullet, and it got us into the world of steampunk. So there have been just a number of really great ones along the way. “Vampire Weekend,” which was the first Halloween that our gang celebrated together was a highlight. The two-parters have been a lot of fun to write and getting bigger and more personal. This year was great. I always knew that in the history of the series we had really one opportunity to put Alexis in danger and still be credible and try to find a way to do it in which if it had to do with one of the cases that Castle and Beckett were investigating, my instinct was that Castle would stop doing what he was doing if he was putting his family in danger. So finding a way in which we could do that, but it didn't have to do it Castle's decision to hang out with Beckett, was a big thing for us.

“The Blue Butterfly," that certainly was a highlight of the series.

Was there a party or anything for the 100th?

We had a cake cutting party where the folks from the network came down and celebrated with us. We're fairly close to the end of the season. We're only about a month and a half away now, so my instinct was just to have a bigger wrap party at the end of the year instead of having two parties almost right in a row. So we were able to celebrate with our entire crew. There was champagne, cake. We had a nice lunch down here. So that was fun.

Lastly, arcs of the spring, what can we expect?

Well, in broad strokes, I think any couple who's been together going on a year starts asking questions about the relationship and what they're looking for in the future. If you're a guy, you tend to worry about making a long-term commitment, especially if he's had two failed marriages. If you're a woman, you start wondering, am I wasting my time on this relationship? Is there something else out there? Are we moving forward? Are we not moving forward? So I think that we look to explore some of those questions which are very human, very natural questions at the point in the relationship where these two characters are.

And Lanie/Esposito?

Lanie/Esposito, we've got some nods to that. The Esplanie fans out there should be looking for stuff coming up, little moments.