In the upcoming “Castle” episode, “Under Fire,” Detective Kevin Ryan (Seamus Dever) finds himself in a deadly situation, right at the moment when his wife, Jenny (Juliana Dever), goes into labor. Will Ryan survive long enough to become a father?

We asked the Devers — a married couple in real life as well as on TV — about the episode and the impact of a baby on “Castle.”

Zap2it: What can you say about “Under Fire”?
Juliana Dever: It’s actually one of the most exciting “Castle” episodes that I’ve seen in awhile — and so much fun to work on. But way more dramatic than I expected it to be! We talk about … Kevin is such a father, that kind of fumbling dad who’s trying to get it right. That’s really what we thought this episode was gonna reflect. And my jaw dropped when I read it. It’s a very dramatic entry into the world for Baby Ryan.

Seamus Dever: Oh yeah! Basically, think about the most simple way that the baby would actually arrive. And then put a “Castle” twist on it where lives are in danger, things are in doubt, characters are possibly getting killed off the show. It’s that kind of episode.

Can you describe any of the plot and the danger Ryan faces?
Seamus Dever: Jenny’s past-due. She’s two days past-due, and Ryan’s been checking his phone to make sure that he gets dial tone. He wants to be there for the moment. It’s very important for him to be there and be ready. So in the midst of being there and being ready, Esposito and Ryan go to check out an arsonist target they’re investigating — some arsons have been happening and there’s murder associated with that.

They go to this empty warehouse. And it turns out that it’s the arsonist’s lair and he had it booby-trapped. So a bomb goes off and they get trapped in this room. The whole building’s on fire, nobody can find them. And it’s in doubt whether Ryan’s going to survive, whether he’s going to make it. There’s an awesome scene where Ryan jerry-rigs an old …

Juliana Dever: You’re going to tell the whole episode here!

Seamus Dever: There’s a great scene where Ryan jerry-rigs a hard line on the phone and he’s able to communicate to Castle and Beckett on the outside.

It turns out that Jenny has shown up to the crime scene, watching this warehouse on fire. And he gets to say goodbye, essentially — “I’m not going to be there.” I’m really looking forward to that. It was some good work by everyone.

What was it like to work with babies on “Castle”?
Seamus Dever: There’s always stuff with babies! You only get like 15 minutes with the baby … It’s like, “You’ve got 15 minutes. Go!” Like with a stopwatch. And everyone has to work very quickly and make sure the scenes are there. But we’ve had very good luck with that lately. We’ve had some good times with that.

Obviously the baby will affect the Ryan family, but how might the new addition impact the rest of the “Castle” characters?
Seamus Dever: We’ve sort of covered it in the last episode, where Beckett and Castle are considering if they’d want to have a child and that sort of thing. And maybe Esposito starts to think about maybe getting serious about something in his life.

Does the new baby mean that we’ll be seeing more of Jenny in upcoming episodes?
Juliana Dever: We actually never know! There’s a lot of ground to cover with “Castle,” with the relationships of the main characters and some of the crimes that they solve. So I have no idea.

Seamus Dever: We hope so. Because it’s fun having Julie around!

“Castle” airs its “Under Fire” episode Monday (Jan. 6) at 10 p.m. on ABC.

Posted by:Laurel Brown