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: Okay, so, honestly, this is probably NOT what we need tonight. It's angsty and dark, and for that I apologize, but this is where we are in this story, and, unfortunately, my imagination does not automatically create fluff for the dramatic Castle episodes (well, I mean…it does…but not for my chapter fics, haha). Anyway! Feedback is always much appreciated. Hang on gang, it's about to get very serious:

Chapter XXII

"Did we get a trace?" Kate asked as they stepped out of the elevator at the 12th.

A uniform looked up at them. "Yeah. Pay phone down by the docks, West side."

"Alright, have you called Ryan and Esposito?"

The young woman nodded. "We sent them down. They'll be waiting for you."

"Thanks. Come on, Castle."

And back down they went. The ride in the elevator was tense. The walk to the car was silent. Once Kate pulled out and they got onto the avenue, she felt Rick's hand engulf hers.

"How bad is it?" he asked quietly as they waited at a red light.

"I don't know, we haven't gotten there yet," she replied, rolling her eyes.

His hand tightened on hers. "No, that he's changing his game."

"Oh," she sighed and glanced over at him. "It's…it's not good, Rick."

"I mean, I know he's violent, obviously, but this isn't his game. He was all about women—blond women. It was a thing about his mother."

"How do you know that?" she asked.

"When he had me tied up last time, I…" he let out a breath, "I sold him a story, profiled, tried to find out what made him tick."

"Of course you did." She didn't know whether to smile or smack him for egging on a serial killer. He was safe now, so she settled on looking disapproving.

"Yeah, not one of my better moments, I'll admit. But, I did find out that I was right. It was his mother; he was neglected, unloved, and then she died. And now…"

"He gets back at her by killing other women," she finished for him.

"But that's just it. He's targeting you, me, my family…this is too different."

"Sometimes these things 'mature' over time, and people become more deranged. I mean, think about Scott Dunn. He didn't start out writing books about his killings. He probably started out by torturing small animals and lighting things on fire."

"Right," Rick nodded. "But why us? Why now?"

They pulled up to the dock and parked. There were a number of other cars already stationed there, flashers throwing glaring light over the quiet water and wood.

"Maybe because we ruined it for him," Kate replied as they got out. "You spelled it out for him. No, Rick," she held up a hand as she watched his face fall. "I don't mean that you did something wrong. All I'm saying is that he may have had an insight after your confrontation, and that led him to either moving past just his mother, or made him more angry."

"So it is my fault."

She grabbed his arm and pulled him to stand in front of her. "A wise man once told me that he wasn't sorry for writing a book that caught the attention of a serial killer. He told me that he wasn't sorry because if he hadn't written it, there never would have been anyone smart enough to catch the guy."

"This is different," he mumbled. "I'm not you."

Kate grabbed his hands. Screw protocol. "No. This is bigger than that. What you did, Rick, might be the only thing that will ever let us catch him. Without that catalyst, he may have moved on, gotten away, gone on a killing spree somewhere else. You kept him here. And I know it doesn't seem like it now, but this is good, Rick. This is going to let us get him."

He met her gaze. "You think so?"

"Yes," she replied, taking the strength to have confidence from the feel of his hands in hers.

"Okay."

"Uh, guys?" Esposito called to them.

They turned and made their way to the anxious looking pair of detectives who were standing near the edge of one of the docks.

"What's wrong?" Kate asked as they drew closer. Neither said a word.

Kate looked down at the body then violently took a step back. She collided with Rick's chest. He was barely moving.

A teenager stared back at them. She had lifeless green eyes and light red hair. This time, there was nothing peaceful about the body. Her eyes were wide in shock and her cheek was bruising. Her right arm was bent at an unnatural angle, and it stuck out of her body almost grotesquely. Blood was oozing out of her thigh and they could see bruising starting to blossom around her neck.

"Do…" Kate's voice stuck in her throat. "Do we have a name?" Ryan nodded and silently passed her a bagged ID and wallet. Kate had to take a few deep breaths before she spoke. "Lexi Castlion?"

"Yeah," Esposito said quietly. "There isn't much sign of a struggle. We're, um, getting in touch with her parents now. She's got a worker's badge on her though. Looks like it's her Dads. So maybe she was down here grabbing something."

"Okay. Is Lanie on her way?"

"Right here, Girl," the woman in question replied. She stepped up beside them and then gasped, throwing a hand over her mouth to try and stop the sound.

Kate turned her head to look at Rick. He hadn't moved an inch behind her and she could tell that he was barely breathing. After a moment, she heard Lanie set down her back and begin to prepare to examine the body. Rick didn't need to see it. Hell, she didn't need to see it. She took a step forward and then turned around, reaching a hand out to give Rick's shoulder a gentle push. He allowed her to turn him away.

"What have we got?" a new voice asked. They looked over and found Jordan striding toward them, determination written all over her tired face. "I hear you got a call, Becke…" she trailed off as she spotted the body. "Is that?"

"No," five voices answered.

"Sorry," Jordan said quietly. She looked around at them for a moment and then knelt next to Lanie. "Castle, Beckett, go back to the Precinct and run down what you can on that wallet," she directed, pointing to the pouch Kate still held limply in her hand. "You two," she turned to Ryan and Esposito, "canvass for witnesses. Now, Dr. Parish, what can you tell me?" she asked, looking at Lanie. The four didn't move. "Are you waiting for an invitation? Go!" Jordan barked.

Ryan and Esposito turned tail and hurried away. Kate gently grabbed Rick's arm. "Come on, Castle. Let's go."

She led him away and back toward the cruiser, keeping an eye on him out of her peripheral vision. She guided him to the passenger side, opened the door, and then turned to him. "Rick," she said gently, willing him to meet her eyes. "Please, get in the car."

He nodded and got in. She closed the door after him and all but sprinted around to get into the driver's side. They just sat there for a minute, staring blankly ahead. She reached over and found his hand. It was clammy and sweating.

"Rick," she started.

"No," he shook his head. "You can't tell me there's a bright side to this."

"You're right," she murmured, stroking her thumb over the back of his hand. "I can't."

After a moment, she relinquished his sweaty palm and started the car. They pulled away from the curb and sped off toward the station. She noticed Rick playing with his phone, his face ashen.

"Call her," she said.

"It's 4:30," he replied.

"Rick, call her. Just tell her you wanted to say I love you."

"I shouldn't wake her."

They came to a red light and she looked over at him. "Please, call her," she asked.

His eyes widened when he met her gaze and he realized that she was worried too. He nodded and pressed his speed dial.

"Hi, pumpkin," he said gently.

"Dad? What's wrong?"

"Nothing, sweetie, nothing. I just…I just wanted to tell you that I love you."

He heard her gasp on the other end. "You're not being held hostage again, are you? Oh, God, Dad, are you?"

Kate extended her hand for the phone and he gladly handed it over. "Alexis? Hi, it's Kate."

"Kate? You're not being held hostage, are you? Um…you couldn't tell me if you were, right? So, um, if you are, say, uh, apples. If not, um…say beets."

"Beets, Alexis," she replied, feeling her heart ache for the poor girl. "We're safe, I promise. We're in the squad car. I can even have Captain Montgomery confirm it, if you need me to."

"No, no," she laughed a bit, but Kate could tell that they'd really scared her. "I believe you. Can I ask you something though?"

"Anything."

"Why are you calling me? I mean, why is Dad calling me? And why are you in the car this early?"

Kate glanced at Rick. "We're running a lead."

There was a pause. "There's a body that looks like me, isn't there?" she asked very quietly.

Kate bit her lip. "Alexis…"

"No, it's okay. Could you hand me back to my Dad?"

"Sure," Kate breathed out. "Just know, that, uh…"

"Love you too, Kate."

Kate felt her breath catch. "Me too, Alexis."

"I know," Kate could hear the smile in her voice. "Now gimme to my Dad, so I can assure him that I'm still alive."

Kate gave a feeble laugh and passed the phone back to Rick. She smiled as she listened to them talk, hearing snippets of conversation on their end. Alexis loved her. Alexis Castle loved her. And she'd…well, she hadn't quite said it back, but Alexis understood.

She had the love of her…boyfriend? Was boyfriend really the right word for Rick? Partner. Partner was the word. He was much more than her boyfriend. She had the love of her partner's daughter and the man…well, they'd basically exchanged those three big words just two hours earlier. She smiled. It was faint, and the rest of her was still too horrified by the body they'd left with Agent Shaw, but it was there.

She pulled into the garage at the Precinct just as Rick hung up. He turned to look at her, the same very faint smile playing on his lips. "She's okay," he said.

"Yeah, she is," Kate replied, leaning over to rest her forehead against his.

"I hate this, Kate."

"I know," she replied, reaching up to cup his face. "I know."

"How many more? How many more people is he going to kill because of me?"

"Not any more, if I have anything to say about it," she said firmly. "And it's not because of you, Rick."

He sighed and pressed a chaste kiss to her lips. "Let's not run through it again. I'll believe you, someday."

She nodded against his forehead and then they separated and got out of the cruiser. They walked into the building together, their sides pressed against each other. The ride in the elevator was silent. They got out on the bullpen and Kate moved to the murder board. She put down the time of the call with Tyson and the name of their victim before sitting down in her chair and flipping on her computer. A uniform came by and she relinquished the pouch with the wallet and ID. All the while, Rick sat in his chair, staring at the murder board, his hands twisting nervously in his lap.

They were silent for a long time. Kate ran through her email and sighed. It would take at least another 15 minutes for the lab to send back any possible prints or come up with anything from missing persons. She glanced over at Rick and found him smiling slightly. It was a sight she realized she'd been desperately missing.

"Alexis absolutely adores you, you know," he said.

"It's mutual," Kate smiled, looking over at him.

"I do too, for the record," he said very quietly.

"You're not so bad yourself, Castle."

I just had to. I'm sorry.

PS. No spoilers for the LA episode in reviews please. I have yet to see it (you lucky Canadians!)