Post-TSATQ, goes AU towards the end. A/N: In my version, Still comes before TSATQ, which was the original airing order. The end of TSATQ has never sat right with me; I don't hate the episode like a lot of people do, I think Kate has a legitimate question that Castle deflects for some reason. This is my version of how the episode could have continued. (cover art is a lightened screen cap from homeofthenutty-dot-com)

BACK TO THE SUN

Let's cut all the ropes and get lost in the moment
If our hearts are alive, maybe then they might
Send us back to the sun
When We Were On Fire – James Bay

The massage is heavenly. It's long, and relaxing, and it's exactly what her body needs after a long day at work. She's so very lucky to have a boyfriend like Castle, who pampers her with no expectation of anything in return. She should be thankful. She should be curled at his side, snuggled next to him, because even when they don't make love, that's her favorite way to fall asleep.

And her second-favorite just happens to be how they're laying now, him curled protectively at her back. His big arms envelop her, one over her waist and the other curled above her pillow. She usually falls asleep right away when they're like this.

Usually. But not tonight.

Kate finally gives up on sleep sometime after one. Castle's been lightly snoring for almost an hour, which usually relaxes her, but tonight she can't turn her brain off.

She can't stop thinking about the last few days. About Eric Vaughn. Not like that; yes, he's good-looking and charming, but he's not the man she's in love with. And yes, she had let him kiss her. But there was nothing. No spark, no wave of arousal she feels every time she kisses Castle. Even that first kiss, the brush of his lips against her cheek the very first day they'd met, she'd felt something. But with Vaughn, there was absolutely nothing.

She's a little ashamed of herself right now. Okay, a lot ashamed. She let another man kiss her. What the hell is wrong with me?

She manages to extract herself from Castle's arms and slides out of bed without waking him. She stares for a few moments while she slips on her robe. He looks so peaceful when he's asleep; while he's made a career out of watching her all the time, she loves turning the tables on him. Watching him sleep is one of her favorite things to do. His hair flops over his forehead, and his lips slightly part when he breathes. His little snore is comforting; she has a hard time sleeping apart from him.

God, she is so completely in love with him. Yet she let another man kiss her.

Shit. She's messed this up. Royally.

Kate feels her eyes burn with tears and pads out to the kitchen to get a glass of water. They'll talk in the morning. She'll call in, go in late to work, maybe take the whole day off. Whatever it takes. Because they are way overdue for this conversation.

Castle wakes to an empty bed. He rubs the sleep from his eyes and swipes his hand across Kate's side of the bed. It's cold. She's been gone for a while.

He's not a stranger to waking alone, in the middle of the night or early morning. Sometimes the night still gets to her, and she doesn't always want to wake him, especially if she needs to be alone for a little while after the subconscious panic sets in. And although he usually leaves her to fight her demons (because on those nights, nothing he does or says can help her), tonight feels different.

Maybe it's the remnants of their earlier conversation. Or, her attempt at a conversation. He didn't realize until she'd drifted off during her massage that "to the bedroom" was not the answer she'd been looking for when she'd asked where they were going. But by then, the moment had been long gone, and when he gave an inquisitive "Kate?" she'd only climbed into bed and patted the space behind her.

Castle looks around now, searching for any sign of her whereabouts. He sees the cracked door to his office; he distinctly remembers closing it while setting up the bedroom, to enhance the romantic atmosphere. He climbs out of bed and walks softly to the door, where he freezes at the sight.

Kate is standing in front of the large window, staring at the city below. He can't see her face, or hear her, but he can tell by the shake of her shoulders that she's crying. He sees a hand move, presumably to swipe at her cheeks; the only thing his girlfriend hates more than being upset is being so upset that she cries.

What have I done?

He walks up behind her, their eyes meeting in their reflection moments before his hands are on her shoulders.

"What's wrong?" he asks softly, holding her gaze.

Kate lets out a slow, shaky breath. "Nothing. Couldn't sleep. I'm just tired."

"Like hell it's nothing." Castle lightly squeezes. "Kate." He continues when she remains silent. "I'm sorry, Kate. I'm sorry I didn't get what you were asking. But mostly I'm sorry that I haven't been clear what my intentions are with this. With us."

"I'm sorry that I let him kiss me," Kate blurts out before he can continue. She turns and locks her arms around his waist. "I love you, Rick. You are the only man I want to be with, and I shouldn't have doubted you, shouldn't have let Vaughn think that he had a chance. Because he didn't. He never did, because my heart already belongs to you. It always has."

Her lips are on his before he even registers all of her words, but he recovers enough to pull away when she reaches for his shirt. "Kate, wait. We need – I need to say something. Just – come here." He leads her to the couch, but before he sits he takes a short detour to his desk. He resumes talking when he grabs what he's looking for.

"I made you doubt, Kate. Three weeks ago, you were standing on a bomb, and I have never felt so devastated at the thought of losing you. Not that day in the cemetery, not any of the other times our lives have been in danger. And then I acted like a grade-A jackass and made you think you weren't important to me. You always have been."

By this time, he's sitting next to her on the couch, his right hand holding her left. "Kate, you are one of the most important women in my life. I'm sorry I was jealous and upset. I had no right to be. But I also realized that I've never come right out and said just how deep my feelings are." Castle holds out his left hand, and when Kate sees the ring, she gasps.

"Rick—"

"Please, let me finish." At her small nod, he continues. "I love you, Kate. I've always loved you. And I know we haven't talked about it, about where our relationship is going. But for me, the endgame has always been forever. And if you're not there, or you need to think about it, that's—"

"Yes." Kate can't hold it in anymore; she grabs his face in both hands and pulls him into a kiss. She swipes her tongue across his lips and he opens them with a groan, but when she shifts her body closer he pulls away.

Castle searches her eyes but sees nothing except love. "So that's a yes as in…" He trails off.

Kate grins. Leave it to her writer to lose his words at a time like this. She kisses him again, softly. "That's a yes as in 'get that ring on my finger,'" she says lightly. Castle flashes her a brief smile before taking her hands, and they both grow serious when he slips the ring onto her finger. Kate stares for a moment, blinking back tears as she brings her gaze back up to her boyfriend.

Fiancé.

Holy shit.

"I love you so much," Castle manages to get out around the lump in his throat. He cups her cheeks and kisses her again, slow and deep, and he lets one hand drop to her waist. He works at her mouth, tongue exploring, smiling against her lips at the moan that escapes her throat.

Kate eventually has to pull back for air, and cards her fingers through his hair when he takes advantage and trails his lips down her neck. "Castle," she breathes, can't help but slide onto his lap when he grips the back of her knee and pulls.

Rick is finally able to pull away so he can look at Kate – his fiancée – and grins at the completely turned on look on her face. He grips her thighs with both hands and stands up, carries her into the bedroom where he deposits her on the bed. He hovers over her, staring, resting most of his weight on his forearms.

After what feels like hours of Castle staring, Kate begins to squirm uncomfortably. She knows he watches her, but watching him watch her is a little weird. "What?"

Castle shakes his head slightly. "Nothing. I just—sometimes when I wake up I just have to look at you, remind myself that you're here. That you chose me. And now?" He finds her left hand and holds it between them. "I'm just blown away, that's all."

Kate twists her wrist so she can brush a kiss against Castle's knuckles. "Preaching to the choir, Castle. So, what do you say we celebrate?"