She is in shock.

She was not expecting this. She thought he was going to say it was over, that he couldn't take fighting for her anymore. That he was tired. She was prepared to get her heart broken by the man she loves.

But there he is, down on one knee, in a place a sacred to them, asking her to marry him. She looks between him and the ring as her mouth continues to widen, watching the sunlight glint off the edges of the beautifully set ring. She doesn't know what to say.

"Rick…", she begins.

"You don't have to answer now, if you don't want to," he says. "But I want you to know that I am ready. We've been doing this dance for five years, and I want more. I want us to still be left after the music stops. I'm not making you choose. This isn't an ultimatum. I want you to know that no matter what you decide, whether you take the job in DC or not, that I'm not going anywhere. That I am here in the long run. That no matter what you decide, I won't leave you."

Her eyes shift solely to the ring as he continues to speak.

"This job in DC is a great opportunity, and you deserve it. You're the best cop I've ever met. No one can catch the bad guy like you. And if it's something you really want, I support you. One hundred percent. But I don't want that to be the end of our relationship. I never want it to end. I can write from anywhere, it's one of the perks of working from home. And maybe Nikki Heat could use a change of scenery. Kate, I love you. You are the best thing that's ever happened to me, and I'm not going to lose you. I won't."

She looks back into his eyes. This is him, being open and honest about their relationship. What he's been avoiding this whole time. And he's doing it with a ring in his hand.

"Like I said, you don't have to decide now. You can think about it. But just don't say no."

She gets up off of the swing. He begins to worry he's been defeated, that she's leaving without him and wants to end what they have. But once she's standing, she walks over to him and kneels down, eye to eye.

A million thoughts are going through her mind, but she does the one thing she wants to most. She leans over and hugs him. This man, who has been such a large part of her life for the last 5 years. Who has completely changed her and how she feels about many things in the world. This incredible man.

He grips her tight, not wanting to let go for fear of losing her for good.

But then she shifts, her head resting on her shoulder, her lips turned in towards his ear, and he hears the faintest of sounds that gives him hope. A simple whisper. A "yes".

Now he's the one who is shocked. She pulls back and looks at him smiling, tears filling her eyes, a thousand thoughts clearly rushing through her head.

"Wh-What?" he asks.

"I said…yes", she begins. A smile forms on her face. "Yes, Richard Edgar Castle. I will marry you."

She kisses him, his look of surprise turns to one of joy and excitement. They kneel there, on the ground, embracing each other tighter than ever before. She pulls back with a grin, her hands resting at the nape of his neck.

"I decided not to take the job," she tells him.

"What? Why? Kate…"

"Let me finish," she interjects. "It is a great opportunity. It is something that I want. But if I go to DC….This is my home. Everyone I care about, everyone important in my life is here. Everything that changed my life, too. Everything that made me realize I wanted to be more than who I am. If I go to DC, the job will be my life. It'll take up most of my time, and my family and best friends won't be there when the day is done. While it's completely logical to take the job, my heart wants me to stay here. And someone once told me that risking our hearts is why we're alive. I'm willing to take that risk. Stay with the people I love, who I also happen to work with, or let the work become my life. Those are my options. And there's no way I'm losing the home I've made here. I won't do that."

His look of surprise has yet to falter, so she continues.

"So, though you were so kind as to offer to move to DC to be with me, it's not going to be a problem. I'm staying. And so are you. And we're moving forward with our relationship," she looks down at the ring still gripped between his fingers. "If you ever put that thing on me."

He glances to where she's looking and lets out a quick laugh, a smile blossoming onto his face. "May I?"

She lets go of him and stands up, left hand pointing down, with a serious-but-funny look on her face. "Go for it, man."

He takes her hand and gently slides the diamond onto her fourth finger. It fits perfectly, of course. She smiles and looks at him as he rises to his feet, happiness shining throughout his features. He pulls her close, and she wraps her arms around his neck. The kiss quickly, and let their foreheads rest together once they've pulled apart. "I love you, Kate," he says to her.

She stares into his eyes, the smile still resting comfortably on her face. "I love you, too, Castle."

They look at the each other for a few moments before leaving the swing set hand in hand. They both know this changes everything. They both know it means they're stuck together. They know it means there's no going back.

And they both know there's no one they'd want to be diving in head first with besides each other.