The Insider.com

The Caskett kiss heard 'round the world wasn't the only explosive development in Castle's fourth season finale -- not only did Beckett and Esposito turn in their badges, but, to some degree, Ryan went against his fab foursome by towing the line.

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So where will season five pick up? How long will the team stay disbanded? What's next for Castle & Beckett's burgeoning relationship? To get those answers, and more, I caught up with Seamus Dever, who plays Detective Kevin Ryan, and found out that while season five won't be as heavy as last year, it will still bring major drama!

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A Team Divided
With Beckett, Esposito, Ryan and Castle scattered about, professionally-speaking, at the end of season four, we're dying to know how long it will take until someone shouts, Avengers Assemble! "We're gonna tease that out in the beginning to see how they come together," Dever tells TheInsider.com, but adds, "The bottom line is, they have to come back together -- they do everything on this show, that's what this show is. But it's not a quick, easy get back together."

Broken Bromance
And while the team may reassemble, fixing what's been broken between Esposito and Ryan does take a little bit longer -- but a grand gesture by Ryan in episode two heals all wounds. Except one. "Ryan makes a physical sacrifice in protecting Esposito," Dever tells me. "There's no talking about feelings, there's no discussing, it's just something dudes do. And it's kind of poetic. When the audience sees it at the end of episode two, they'll know, 'OK, this is how they make up.'"

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A Kiss, Four Years In The Making
Good news Castle fans, the show has no plans to pull a Moonlighting and wish the kiss away. Although, according to Seamus, Castle and Beckett's relationship won't be going public any time soon. "[When we pick up], the great fun is, no one knows about their relationship," he tells TheInsider.com. "There are moments where Esposito is suspicious about something and there are moments when Ryan gets suspicious over lingering looks, but they redirect attention. It becomes a challenge between Esposito and Ryan as to who will figure it out first?"

A Rocky Relationship
Castle & Beckett's relationship also presents professional problems. "The romance has always helped them figure out a mystery," Dever says. "Them postulation on a theory and building on each other's ideas was like foreplay. So can they do real foreplay and still be good crime solvers? Who knows. And if they're placed in physical jeopardy, can they cope with the raised stakes? It's been really neat to see them try to balance their lives before the kiss and their lives now."

New Season, New Crimes
Castle has always created insanely intricate worlds upon which to build their mystery, and season five will be no exception. While the writers are currently tinkering with some ideas on par with The Blue Butterfly (season four's standout film noir-inspired episode), Dever reveals episode three is Storage Wars-themed, while season five will also tackle the local news and a bottle episode set entirely inside a single office. "They want to sell the environment, not just the crime of the week," Dever says.

Lighten Up!
"A lot of people think we got too dark last season in dealing with so many serious character-driven episodes," Dever says. "But that really helped us get to know all of them a lot better and maybe understand them a bit more." But now that Castle has journeyed into the character development tunnel, it's time for the show to emerge. "This season is all about getting back to some of the lightness and the comedy. Everyone's been talking about bringing the funny back. Now that [Castle and Beckett] are together, there is some fun to be mined from that." Although Dever is quick to warn, "some serious stuff happens mid-season, but we're always trying to make sure the funny is maintained."

Castle premieres September 24 at 10 p.m. on ABC.