Credit: IMDB Photo: Terri Miller

The Season 3 finale of Castle had fans gasping, crying and hanging on a cliff after the death of Captain Montgomery (Ruben Santiago-Hudson), the shooting of Det. Kate Beckett (Stana Katic), and Rick Castle (Nathan Fillion) finally saying "I love you" as she lay bleeding in his arms.

So what's next? Castle writer/producer Terri Miller (who's also married to creator Andrew Marlowe) emailed us from an undisclosed vacation spot to answer questions from Wetpaint and our readers about the decision to kill off a beloved character, whether Beckett will live — and if she'll remember those three little words if she does.

Wetpaint: When did you first make the decision to kill off Montgomery?

Terri Miller: It was a cold and rainy Thursday. A mysterious man in a sodden trench coat entered and threw open Marlowe's office door. "The Captain is the third cop, he grunted. He's the key to Johanna Beckett's murder."

Actually, Will Beall conceived the stories for “Knockdown” and “Knockout” as a whole based on conversations we'd had about how we might end the season and the next steps in Johanna Beckett's murder. He worked with Andrew to shape them so they fit in with the show's mythology. It was a decision we did not make lightly. Killing off one of the characters we created, part of our family was as angsty for us as it was for our fans.

Has it always been part of the plan that he was involved in Johanna Beckett's murder?

The decision to make Montgomery a part of the conspiracy evolved out of the storytelling. It was not something we planned going in.

Credit: Bob D'Amico/ABC Photo: Ruben Santiago-Hudson as Captain Montgomery in Castle Season 3

How did Ruben take the news that Montgomery was dying?

Like a pro, like the gentleman he is. He was disappointed not to continue on but understood the creative reasons behind the decision.

How did the rest of the cast react when they first found out?

Everyone loves Ruben and we all feel it's been an honor to work with him. He's a good man, a great actor and across the board, everyone felt like we were losing a family member and an integral part of the team.

Were you afraid of a negative reaction from fans to Montgomery's death?

No. If we wrote in fear, no one would invest in our stories or our characters. We strive for truth in drama and without conflict, tension and suspense, why would you care at all? The greatest compliment of all is that fans have emotionally invested in our characters.

From Pam, a fan on our Facebook page: Will they bring someone new in to take Mongomery's place?

We're discussing that now. We will most likely bring in someone who is perhaps less accepting of Castle's presence and less supportive of Beckett to create more conflict in our precinct.

Credit: ABC Photo: Castle Tells Beckett He Loves Her

Clearly, Beckett will survive the shooting ( I believe Andrew's already spoken about her kicking around next season). And her mother's killer is still out there. Will that be a big arc next season as well?

Lets just say that it's something our characters need to deal with and leave it at that. Assuming Beckett survives!

From Terri on Facebook: Will Beckett remember Castle's "I LOVE YOU?"

That is something we will all be wondering. Did she hear him before she passed out? If she did, will she remember? Will Castle tell her again? If she does remember, how will she react? Will she even live? All good questions. Stay tuned.

Where will Beckett and Castle's relationship go from here?

Assuming Beckett survives, Castle and Beckett's relationship will continue to grow and change. Both have been through a horrible ordeal, the outcome of which has not been resolved. They will have to weather the fallout of Montgomery's death, Beckett's shooting, Castle's realization and expression of his feelings for her AND, they need to continue solving murders. The flow of their relationship will be organic and true to who they are and what they've been through together.

From Jordyn on Facebook: What else can we look forward to seeing and experiencing next season?

More murders. More mystery. More drama and more fun.

Credit: ABC Photo: Introducing...Esplanie!

Will we get to see more of some of the other characters? Willl we get a Lanie episode? Or delve more into Ryan and Esposito's lives?

YES! We have oodles of material to mine from everyone. A good time will be had by all.

Jon Huertas told us that there was some talk about putting Esposito and Ryan at odds. And they got into a fight in the finale. Will we see that bromance go through trouble times in the future?

It's been discussed. Honestly don't know yet, but there are a couple of interesting scenarios.

What's up with Ryan's wedding, will we see that next season?

Well, something's gotta happen, right? Jenny doesn't strike me as the type to suffer a super-long engagement.

Credit: Jesse Grant/Getty Photo: Creator Andrew Marlowe Attends Season 3 Premier Party

From Maggie on Facebook: Do you and Andrew ever disagree on plots or character development?

Yes, we do. There have been a couple of moments when I absolutely felt that a  character would never do/say/feel something that shows up in a draft. Sometimes I win the debate, if I have a convincing argument. But, if we agree to disagree, the showrunner is the decider. However, Andrew appreciates a strong, well-thought-out point of view and considers any intelligent discussion, from any of the writers. We both feel that we have to allow the characters and the show to grow, and it's important to have that conflict in order for that to happen.

What has been your favorite memory from behind the scenes of the show?

The simple answer is, every time i see a scene we've written come to life, whether its one of my episodes or someone else's. Some of my favorite memories are on episodes I've conceived, walking onto the set and seeing what Alfred Sole and his team have created. In "Vampire Weekend" and in "Poof,You're Dead"  the sets were mind-blowing.

I love the prep process when we all talk about our conception of the show, the mood, the look, the concrete aspects of props and costume. [Costume designer] Luke Reichle is so much fun to work with, as are our hair and make-up departments. Everyone is so fantastically creative.

Then, the actors say the words and it never gets old. Sometimes it just makes me giddy. I also had a fantastic time working with Alyssa Milano, hanging out and talking with her in her gorgeous wedding gown; Ii got a huge kick out of planning that wedding. I've been on the show since the pilot so there are so many moments of joy I've shared with the cast and crew, that it would be difficult to isolate one. It may sound corny, but I feel lucky that I get to do this every day.

What other shows do you watch? Any guilty pleasures?

I have way too many guilty pleasures. I am loving Game of Thrones. Glee! Mad Men. Shameless makes me feel very guilty. I love Celebrity Apprentice and I've been a fan of Grey's Anatomy from day one. I never missed an episode of Lost, and when it comes back, I will be a loyal Weeds watcher. One of Andrew and my favorites to watch together is Supernatural.