The Insider.com

The fourth season of Castle ended with a bang, literally, as Beckett and Castle finally consummated their long festering feelings for one another. And you just know there's got to be a morning after -- which is exactly where the fifth season picks up as you can see in this brand new promo!

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"So it wasn't a dream," Castle says in the clip, to which Beckett replies, "You liked it? Me too." [Professional pause: "Squeeeeeeeee!"]

And while Rick and Kate are clearly comfortable to explore their feelings, they're not quite ready for anyone else to know about it just yet, which leads to a series of cute moments that reinforce the fact season five will bring the show back to a much funnier place.

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"The great fun [this season] is, no one knows about their relationship," Seamus Dever 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."

Although, according to Tamala Jones, by the second episode, the pressure of keeping this secret is putting Caskett on edge. "There's a scene in the second episode where it appears Lanie knows something because she sees a glow on Kate's face, and girlfriends know when their friends are having sex," she laughs. "It's such a fun scene in the morgue where they're almost outed by themselves even though Lanie doesn’t know anything!"

Thankfully, Castle appears to be putting much care into mastering the magic that comes from the burgeoning days of a new relationship -- which is to be expected given how thoughtfully the writers planned the couple's consummation. "It's like you're in the relationship with them, the way its been written," Tamala tells TheInsider.com. "It is such an adventure for the characters and the audience. Plus, Nathan [Fillion] and Stana [Katic] are killing it. Their scenes are unreal. All that chemistry they had before is exploding this season. The show is on fire right now."

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