A "What If" scenario from 3X22 "To Love and Die in L.A." - What might have happened after Kate opened the door during the hotel room scene.

"Goodnight, Castle."

Though they'd escaped her lips, the words still left a dryness in her mouth, a lump in her throat. Her heart in her throat.

She leaned back against the door, feeling its coolness through her thin nightshirt. She just needed a moment to breathe, that was all. A moment to process what he'd said. No, it wasn't what he said. It wasn't the words. It was how he said them. The look—no, the smolder—in his eyes as he spoke. That lingering moment of eye contact they shared.

Every time their gazes locked she felt them. Sparks, butterflies—whatever they were, she felt them. Typically when this happened they were standing at least a foot apart—a safe distance. She could feel the pull, the tug of her heart wanting her feet to get just a little bit closer so she could touch, taste, but her head always held her strong until that moment. Her head clouded and her breath grew short as she looked at him, feeling a pull unlike any other. It wasn't just a string pulling her along, it was several ropes and a metal chain; it felt like gravity.

Her skin began to prickle, her lips began to part and that's when she knew she had to escape—before it grabbed a hold of her, before it swept her in and she could never let go. Fight or flight. Why did she choose fight in every instance except those involving her heart?

She ran her hands over her face as a new feeling hit her: regret. She'd walked away so many times before, ended moments before they even started, so why was this time different?

One foot out the door. It was how she lived her life, how she protected her heart, but was that really living? The pre-Richard-Castle version of herself never would have asked that question; never would have second guessed her choice, but three years after meeting him she just wasn't sure. Now she was the girl who laughed at crime scenes, pranked her partners, and started every morning with a cup of coffee and a smile.

Just take a chance, her heart told her as she lowered her hand to the door handle. Take a leap of faith. If there is one man in this world who will catch you it's him; you know it's him.

She'd known for a while—okay, quite a while—that he had feelings for her. She was, after all, a detective and his schoolboy tendencies were fairly obvious, but she was never certain where they stood. Was it a crush? Was it a quest for sexual conquest? Was it professional admiration? Or was it possible he felt the same thing she did—a palpable, undeniable attraction built over late nights, hard cases, and moments of pure happiness?

The coolness of the door handle under her skin made her breathe in sharply. She knew. Deep down she knew. His feelings for her were true, as were hers for him. He'd proved it time and time again by risking his life to help her and, yes, even to save her. It was time for her to return the favor.

In one swift motion she turned the handle and pulled open the door. Her eyes went directly for the couch, but she found it vacant. On the verge of disappointment, she swept her eyes in the direction of his hotel room door and she saw him, half turned to walk away, frozen upon hearing the door unlatch.

His brow creased as he spoke, "Kate?"

She let out a long exhale as she swept in to the room. "Don't say anything." If he spoke, if he said anything—romantic, ridiculous, or anything in between—she knew she would lose her nerve.

She glided to his side in four steps and froze, suddenly unsure of herself. She trained her gaze on the top button of his shirt and swallowed hard. As though she was reaching to touch the world's most precious gem, she lifted her right hand and rested it in the middle of his chest. After mirroring the action with her left hand she skimmed the smooth fabric of his shirt with her fingers as though testing to see what would happen.

When his hand landed symmetrically on her hips she breathed in sharply and shut her eyes. She could feel the skin prickle at the base of her neck and down her spine. The warmth of his body radiating beside her was almost too much. The heat was almost suffocating, causing her breath to come in quick spurts. She could feel it coming—fight or flight—and tried to suppress it with every ounce of self-control she had remaining.

Five calming in through the nose, out through the mouth breaths later, she looked up at him and met his gaze. There it was again: gravity. She felt the pull of her heart guiding her towards him. As though powered by something far beyond her control her feet slid along the floor several inches towards him. Only when their bodies were all but aligned did she realize it was his grasp on her hips drawing her in.

His eyes darted between hers and her lips as his chin descended several inches. She knew what was coming and her brain made one last ditch effort to compel her to stop by rationalizing that she was just upset over Royce and this wasn't really what she wanted. Oh, but it was, her heart replied. It was.

His lips pressed against her, gently testing the waters. Her fingers slid up and over his shoulders as she fell against him, surrendering.

With his fingers still resting against her hips, he pushed her away and, when her eyes fluttered open, gazing at her almost questioningly. He was following her request not to speak, but she knew he was asking if she was sure, if she was okay. It only made her want him more.

Locking her arms behind his head she threw herself at him, capturing his lips with three years' worth of pent up passion from every moment, every look. Suddenly, kissing him wasn't enough. Tasting his mouth wasn't enough. Feeling his hands running over her shirt wasn't enough.

Never breaking contact with his lips, she turned a hundred and eighty degrees so her back was facing the door to his room. She began backing her way towards it while her hands fell down his torso and she began untucking his shirt.

In her kissing furor, she failed to calculate just how close they were to his room, and found herself crashing into the hard object not ten steps later. Still clawing at his shirt with her left hand, she twisted her right behind her and grappled with the handle before finally pushing it down enough for the door to spring open and for the two of them to crash through it and land in a heap on the floor.

Though the initial impact startled her, their abrupt change in altitude did nothing to interrupt her mission. Instead, she used her new position to her advantage and reclined back against the floor as her fingers hastily worked at the buttons on his shirt. He placed one knee on either side of her hips and ran his hands underneath her top all the way up to the edge of her bra before skimming them back down to the top edge of her leggings, which he hooked with the index and middle finger of each hand. She stopped her work on his shirt as he removed the item from her body. Only after tossing it aside did he realize that she wore nothing underneath.

He could not help a soft, "Jesus, Kate," from escaping his lips at this discovery.

Before he could say anything more, she rolled herself up to a seated position and tucked one leg underneath her. She pulled him with her as she rose from the ground. She turned towards the bed and tore away the comforter, revealing the crisp white sheets beneath. When she spun back around, she saw him hopping on one foot, his pants around his ankles, his shoes still on, as he struggled to untangle the situation he created.

For a moment, she merely stared, half of her wanting to roll her eyes, the other half wanting to laugh. Then she realized that for them that mix of emotions was entirely fitting and perfect.

When he was able to pop his shoe off and thus remove his pant leg, he looked up momentarily proud until he realized she was watching his struggle. His brow dropped and formed that perfect child-with-his-hand-caught-in-the-cookie-jar expression. As stoically as he could muster, he stood up straight, toed off his other shoe, and calmly stepped out of his pants.

Unable to resist, she playfully questioned, "You good?"

His response was instant and full of forced casualty, "Yeah, I'm good."

A slight smile still playing on her lips, she scooped up the hem of her shirt in either hand and pulled it up and over her head. After doing the same with her bra she stood before him, arms at her side just watching his face. His eye skimmed over her as though she was a statue of the deity he worshiped all his life but never before seen in person.

She anticipated an anecdote, a Castle quip, but he said nothing. Instead, he took one step forward and slid his left hand under her jaw before capturing her lips in a feverous duel. His lips moved across her jaw, down her throat and to the valley of her breasts before she dropped down on to the bed with him right behind her.

As his lips paid every inch of her skin the attention it deserved, his right hand slipped between her thighs, his fingers curling against all the spots that made her grab handfuls of the sheets and writhe beneath him. She had no idea when he removed his final item of clothing because she never felt his hands leave her, but suddenly he was over her, holding her steady with his lips tender against hers as their bodies joined together.

In all her life she never imagined anything could feel so wonderful, so right, but there she was, letting him love her, unconcerned for the future, but simply enjoying that moment and everything that led her to it.

Kate awoke with a start. She'd dreamed about being in the alley where Royce's body was discovered, only when she went over to examine the body, it wasn't Royce beside that dumpster; it had been Castle. Her eyes flew open and the room was pitch black; it was only a nightmare.

On instinct, she rolled to her right to see the clock on the nightstand, but something held her in place. An arm draped across her torso and she smiled inwardly at the recollection of whose arm it was. Unable to move her body, she turned her head and craned her neck so she could just see the edge of the clock. 4:13. In L.A. this was far too early an hour to rise, but by New York time she'd overslept her usual waking hour.

She settled back against the pillow and snuggled a bit closer to the man beside her. Castle. He was there with her, not dead in an alley. His arms curled around her to form a perfect nest for her to rest in, just as she imagined they would. Now, after a night of making love, she was finally able to experience a morning beside him.

For the next hour she dozed off and on, mostly lying there listening to his steady breathing. Just before five thirty he began to stir and she nuzzled her forehead underneath his chin, gently letting him know she was awake. He let out a contented sign and tightened his arms around her. "Morning," he mumbled through a yawn.

"Morning," she echoed.

He dropped a kiss on to her forehead before leaning away from her and stretching out his limbs. When he looked back at her, he wore and ear-to-ear grin. "Sleep well?"

"Mmmhm," she nodded. "You?"

He grinned wider, if possible. "Excellently, thank you." He ran the back of his fingers across her cheek and began, "Kate, about-"

"Castle, wait," she cut him off knowing she had to say what was on her mind before she lost her nerve. "I just…I need you to know that I…I have a lot of stuff I need to work through and, God, technically I'm still with Josh and I…it's…I'm not the best at relationships, but I…I'm in this if-if you are."

His eyes widened. "If I am? If I am? Are you kidding me? I am SO in this!"

His unexpectedly enthusiastic response made her chuckle. "As long as you're sure."

"Kate," he said, pulling her closer. "I'm so sure. I've been sure since the moment I met you." With that he captured her lips in a loving kiss.

A smile blossomed across her face when they broke apart. "I just want to make sure you know I want to take things slow—I need to."

His mouth straightened and he nodded his head, sliding a few inches away from her in the bed. "Slow. Right. Totally got it."

"Well," she said, biting her lip as she grabbed his arm and used it to pull herself on top of him. "Maybe not that slow," she said before kissing him. He locked his arms around her waist and held her as tight as he could, never wanting to let go.

"Castle," she added softly when their lips broke. He hmm-ed at her. "Thanks for being here with me."

A smile broke out across his face. "Always."