Title: Rock Foundation

Disclaimer: I do not own the Castle characters or their story lines. I just borrow them for fun.

Summary: A Sequel of sorts for my one-shot Rock Solid. Kate and Rick deal with the aftermath of Knockdown and move forward with their lives, learning to balance their partnership with their budding relationship.

Author's note: So, here's this update. I did it backward this week, just to keep you all on your toes.

I know a lot of you have been interested in drama, so, here it comes. Let me know what you think.

Chapter XXI

"Nothing," Kate sighed, rubbing her fists into her eyes.

It was past 9pm and they were no closer to Tyson than they'd been when Jordan Shaw had shown up that morning. Even with the smart boards and everything they could think of, they couldn't find him.

"We've got an APB on him, Beckett. We'll find him," Shaw told her as she flipped through a file on the first 3XK case. "We've got people at all of his hangouts and eyes on all of his known associates, along with all of the Waters' friends. If he sneezes, we'll hear about it."

"Then why haven't we found him?" Kate asked, looking over at Jordan from her position at the desk in the war room. "How is he still out of reach?"

"We'll find it, Kate."

Kate nodded and glanced through the blinds at the break room. Rick was pacing around while talking on his cell, his face tense. Alexis and Martha had been advised to stay in the Hamptons for the undetermined future, since it was obvious that Tyson was out for revenge. She hated seeing him so upset. He'd been effusive and upbeat all day, but Kate could tell that his heart wasn't really in it. After their argument in the car, they'd been a bit cautious, and hadn't even had the chance to talk about it since they were so busy running down more blind leads.

"So, level with me," Jordan's words broke Kate from her stupor.

"Sorry?"

"You and Castle. What happened there? Last time I talked to you, you were completely against it."

"I wouldn't say against it…"

Jordan scoffed. "Complicated, whatever. What changed?"

Kate considered her question. "We got closer. He's been here for nearly three years and I honestly can't imagine things without him now. And he's been with me through some tough stuff; it just pushed us together."

"He's got your back," Jordan smiled.

"He's saved it a few times since you were here too."

"He's a good man."

"Yeah," Kate smiled shyly. "He is."

"Just be careful, okay?" Kate met her eyes. "Cases like these have a tendency to tear people apart. We got lucky last time, but now he's after both of you, and I don't want to see you go down in flames over it."

"We're working on it," Kate assured her. "It's…it's tough. I want to keep him safe, and he's insistent on being idiotically heroic, which has worked for him in the past, I'll admit. But you can't be that lucky all the time."

"No, but I think between the two of you, you can make sure that neither of you gets killed."

"I certainly hope so."

"I second that motion." Both women turned around and found Rick leaning against the door into the room. "We should head out. Captain says he wants you rested, Detective," he told Kate.

Kate turned and looked at Jordan, who was packing up her bag. "He's right. We'll get a call if Tyson shows up. You've got guards on your buildings right?" Both nodded. "And you promise not to send them home, this time?"

Kate gave a weak laugh. "I promise to be sensible and not do anything to put myself in more danger than's absolutely necessary."

"Thank you."

"Make sure someone checks your car?" Rick added as the three of them left the room.

"Will do," Jordan smiled. "We've got some sordid history between us, huh?"

"Sordid stories are the best kind," Rick smiled.

"If you say so, Castle. See you in the morning," said Jordan.

"Night," they chorused.

Kate moved over to her desk and began gathering her things while Rick leaned against the edge and watched her.

"How're Alexis and Martha?" Kate asked.

He sighed. "They're fine. Alexis isn't fond of being kept in the dark, and she's missing school too, so she's…she's mad."

"Is she mad that you made them leave, or that you didn't go with them?" she asked, laying a gentle hand on his arm.

He met her gaze. "A little of both. I've explained that it's for her safety, not mine, since it's far more likely that he'd go after them if I'm there too…but she's…she's always been really good about the fact that I work with you. But she's seventeen, you know?"

Kate nodded. "I can understand why she'd be mad. I would be too."

"We'll have a long talk when this is all over," he murmured.

Kate smiled and slipped her hand into the crook of his arm to gently tug him to the elevator. Out of the corner of her eye, she spotted Esposito and Ryan hanging out of the doorway to the break room, watching them. She smirked and leaned up to press a gentle kiss to Rick's mouth as the doors to the elevator closed in front of them.

"What was that for?" Rick asked, brushing a hand over her cheek.

"The boys were watching."

"And I missed it?" he gasped.

"Sorry," she snickered. "Don't worry, I'm sure I'll get a very colorful description from Lanie."

"I get those details, right? I mean, girl talk is fine, but…it's about us…" he whined. She grinned; it was nice to hear him being himself.

"We'll see."

"That's not fair."

"Lots of things aren't fair, Castle," she laughed.

They got into the car and waved at the guard who was stationed in the garage. A silence fell between them as the weight of the situation they were in came back down.

"Whose house?" she asked after a moment. Rick shrugged. "What bathtub would you prefer?" she tried.

He looked over at her and took her hand in his. "The one with you in it."

She nodded. "Alright. My place it is."

They drove the twelve blocks without speaking. His thumb rubbed over the back of her hand and she stole glances at him as he watched the city fly by. They needed to find Tyson. She didn't want to have to see Rick like this for much longer.

She led him up to her apartment after they greeted the doorman and police guard. They took off their coats and then stood in the foyer in an odd sense of déjà vu from the night before.

"Rick," she said quietly, bringing him out of his thoughts. "You can't let him win."

He just looked at her. "I had to send my family away. My daughter is mad at me. Do you know how often that happens?" He shook his head and frowned. "And he's gunning for you. I just, God. I hate this!"

Kate nodded and reached for him, but he brushed her off, taking to pacing instead. "He's sadistic and whacked. And I let him get away. If I hadn't said anything about the damn bag, we could have kept him there, or followed him and gotten him and none of this would have happened!"

"Rick," Kate tried.

"It's my fault that he's still out there. Don't you get that? This is my fault! My family's in danger because of me!"

"Richard Castle," Kate exclaimed. His eyes snapped to look at her. "This. Is. Not. Your. Fault."

"But it is…"

"No, listen to me." She approached him again and took his face in her hands so that they were eye to eye. "You couldn't have known that he was the killer. We're lucky you're not dead right now. He would have knocked Ryan out and tied you up whether or not you'd said something about the duffel. It's not your fault. It's his fault. You can't blame yourself for this."

"But…"

"Rick," she sighed, pressing her forehead to his. "It's not your fault. You can't blame yourself for those murders. This is Tyson. And we're going to get him, together, you and me. And then you can bring your family back."

"I just feel…"

"I know," she whispered. "I know, Rick. But you can't let him win before we've gotten the chance to take him down, okay? You can be upset; hell, I'm livid. But you can't let him win."

He took a deep breath and nodded. "Okay."

"Thank you," she said as she leaned in and kissed him. "Do you want some wine or something?" she asked as they pulled apart a minute later.

He shook his head and tugged her toward her bedroom. He guided her over to the bed and pulled her down beside him so that he could wrap his body around her, hugging her close, her back against his chest.

"I can't bring my whole family back," he said quietly a few minutes later.

"What do you mean?"

"You're already here," he whispered.

Kate felt her chest tighten. He pressed a kiss to her ear and she scooted away to roll over so that they could see each other.

"I mean it," he continued as he ran a hand up and down her side while she toyed with his collar. "You're part of me—part of my family—part of my everything."

She felt butterflies erupt in her stomach as she searched his eyes. No one had ever looked at her like that before. Days, weeks, months—it didn't matter. He'd become her everything a long time ago, before she'd ever wanted him to. And now he was hers and she was his. "You're my family too," she told him.

He leaned down and kissed her with everything he had and she met him bit for bit. They lay there together, bodies wound tightly around each other as their mouths spoke more words than they could possibly say.

Hours later, they fell asleep, still fully clothed, Kate's head nestled beneath Rick's chin, and their bodies as close together as humanly possible.

…

The call came at 3am. Kate extricated herself from Rick's grip to grab her cell from the nightstand, smiling as he groped for her, his eyes still shut.

She groggily pressed the call button. "Beckett."

"Good morning, Detective."

Kate sat up straight and shook Rick's shoulder. "Who is this?"

"I think you know who this is, Detective," the cold voice informed her.

"Jerry Tyson," she said through clenched teeth. Rick shot up beside her and leaned in, wrapping an arm around her shoulders.

"Tell your shadow I say hello as well." He sounded smug and Kate felt Rick's fist clench.

"Why are you calling me, Tyson?"

"I figured I should give you some help."

"Help?"

"You're not doing a very good job of finding me. And the longer it takes, the angrier I become. And when I get angry," there was a scuffling sound on the other end of the line. "I tend to get violent."

They heard a short scream before the line went dead. Kate felt her hand drop from her ear and they stared down at the phone.

"Shit," Rick said after a second.

"You've got that right," Kate muttered as she hit speed dial one. "Yes, dispatch, this is Detective Kate Beckett. I just received a call from Jerry Tyson. I need a trace on the last call made to my cell phone. There was a victim on the other end with him. Yes, we'll be there."

She hung up and climbed out of bed. "Come on, we've got to go to the station."

Rick was up and running into the bathroom an instant later. Kate watched him go and sighed, moving to change her clothes. Tyson was toying with them, which didn't fit anything they knew about him. Kate didn't scare easily. Even when Scott Dunn had blown up her apartment, she hadn't been scared. She'd been spitting mad, but not frightened, even if she did still feel a slight sense of unease whenever she showered alone.

But Tyson was targeting them in the most gruesome way. He'd completely changed his Modus and was escalating with a speed that put chills down her spine. A changing serial killer was about the worst thing a cop could find. And he was after them.

She couldn't fight it. She was scared. From the look Rick gave her as he came out of the bathroom, he was too. He stopped her before she got to the bathroom door and suddenly they were kissing with a feverish intensity that left them both spinning.

"We'll get him," she whispered as they finally pulled apart, chests heaving.

"We'll get him."

They looked at each other for a moment before Kate began walking into the bathroom, unsaid words hanging in the still air.

"I…" Rick started.

Kate turned back to him. "I know. And I do too, but I want this moment to be about us and only us."

He gave her a soft smile. "You got it." He leaned in and gave her one last chaste kiss. "Get ready, I'll make coffee."

Author's Note, the Sequel:

Thank you to everyone who has been reading and reviewing this story. Your support has been so important and encouraging. And thank you also to everyone who has read and reviewed my other stories. You've completely embraced me as a member of this community, and it has made these past few months into something really wonderful for me. I'm constantly floored by your responses and you've made me love writing so much that I barely stop anymore (which is great for the heart, but admittedly hard on the grades!) So, thank you for all of your support. You guys are the best. 3

Emma