Doomsday

"Dad?"

"Oh shi-" Kate scrambled to get her shirt back on before Alexis knocked on the door. Castle was totally not helping; she batted his hands away and gave him the evil eye.

"Dad, is Missy in there?"

Missy?

"Missy?" he called back, straightening his tshirt as he headed for the door. He glanced back once to her, and she nodded, so he opened the door.

Kate crossed her arms over her chest, hoped the heat just under her skin wasn't being broadcast quite as blatantly as it felt like it was. It probably was. Her cheeks were on fire.

Alexis glanced between them in the doorway, then shook her head. "We're missing the twins' little sister, Melissa."

"The twins have a little sister?" Castle gaped.

"Missy. She's almost two."

"She's not in here."

"We've looked all over. This is the last place she could be."

Kate closed her eyes, tried to block out the idea of tiny little girl getting scarred for life while she and Castle - oh jeez, oh please no.

"Have you two been fighting?" Alexis asked.

Castle shook his head in denial, glanced back at her for help, but Kate was having trouble catching her breath, having trouble shutting down the wicked, vengeful arousal that still buzzed in her ears and made her body vibrate like electricity in an exposed wire.

She waved him off, shaking her head at him.

"Dad. Kevin said that Missy hides when people are fighting. If you were fighting, she probably hid in here somewhere."

Oh no. No, no, no. Not after Castle had his hand-

"Let me look-"

"We'll all look. Right, Kate? But I bet she's not - oh."

Kate opened her eyes and saw Castle standing at the foot of the bed, two little blue eyes, blonde hair peering out from underneath it. Alexis was coaxing the girl out slowly, talking in low tones, and Kate groaned, put her head in her hands.

When Alexis had the girl in her arms, she carried her to the doorway. "You guys shouldn't fight. It's Christmas."

If she could disappear through the floor right now, if the bunker's concrete foundation could just open up and swallow her, oh my word, please-

"We weren't fighting," Castle protested meekly.

"Were my Dad and Kate fighting, sweetheart? I'm sorry. I know. But they really do love each other. They won't fight anymore," Alexis sweet-talked to the girl.

Missy stayed silent, blue eyes watching them accusingly. She knew. She was judging them too. Of course she was. She just witnessed, or at least heard, two adults who couldn't even-

Kate wiped her hand down her face, realized that was such a Castle move and stopped, dropped her hand. "We weren't - we were fighting at first. But not for long."

Castle gave her a bug-eyed look and Alexis blushed crimson.

Oh. Oh, that said too much, didn't it? "I - I mean. I - we - uh. Castle." She cut her eyes to him, begging for help, but he was slowly shaking his head, blinking at her like she was from another planet.

Alexis shifted in the doorway. "Did you - are you together?"

"No," Kate said.

"Yes," Castle grunted.

Kate jerked her head towards Castle, opened her mouth, closed it.

Alexis snorted. "Uh-huh. Well. I guess you've got until midnight, right? That's when the evil curse of December 21st is over. I'm gonna take Missy to her mom. Maybe you guys should stay in here until you figure it out."

Kate stared.

Castle cleared his throat. "Did you just - are you sending us to my room?"

"Sure, if that's what it takes," Alexis said, her jaw set as she glared at them both. "Fighting is stupid. But the not for long part? That's even stupider if you don't know what you're doing here. Be together or don't be together, guys. But just figure it out."

She slammed the door behind her, the force of it rattling the picture frames on the bookshelves.

Kate turned horrified eyes to Castle.

He gave her a wincing shrug. No help.

No help at all.

He stared at his feet and tried to think of something to say.

"We're not really-" Kate started, stopped. He looked up at her and she frowned. "We're not really . . . grounded are we?"

"I - I think so."

"But. You're the parent. Not her."

"Ah. Well, not always." He winced and tried to see how she was taking that. Not so hot.

"Not always?" She huffed and stalked away from the door, away from him. "Well, that's healthy. Great."

He sighed, rubbed his hands over his face - hard - tried to scrub some sense into himself. He was still mentally undressing her, shirt off, hands heading for her jeans, but that wouldn't help anything right now.

As Alexis had pointed out to them.

"Sorry," Kate said, coming back. "Not like I can talk. My father didn't exactly hold on to that role very well either. So - okay. Um. What do we do now?"

He lifted his eyes to her, eyebrows raising as well, tried to figure out if she was being serious. She was. She really meant that.

"As you - as you pointed out, we're the parents, not her - oh. I - I mean-"

Her mouth had dropped open.

He backpedaled quickly. "Just, a phrase. I meant. You know what I meant." Only, yeah, crap, he'd meant parents just like he'd said it and not because Kate was Alexis's stepmom or anything, but he just - he'd spent so much of these last few years asking for her help in being a good parent to a daughter that it felt natural to call her one too. Sort of.

She ran a shaky hand through her hair and stalked away again, then back. He didn't know what to say.

"Okay. So. Since we're switching places with her here - Freaky Friday or something - we do what she said. Figure it out." Kate bit her bottom lip, and he saw the insecurity wash over her face. So she talked a good game, but she was as afraid of this as he was.

"Figure it out," he replied slowly. He didn't want to figure it out. Figuring it out would lead to No, Castle, you can't.

And he wanted to.

She turned towards him. "Are we . . . fighting or are we-"

"Not fighting," he finished, staring at her.

"Not fighting?" she asked, hope slipping through her eyes.

Oh, that wasn't an answer, it was-

She must've seen it because she tilted her head back, as if stopping tears, turned her cheek, arms crossed over her body.

Like it was his fault they were fighting? "Kate. It's your choice. I-"

"My choice?" she said heatedly, turning back to him with all trace of sorrow up in the flames of her anger. "My choice? I told you my choice. I love you and you're being an idiot-"

He grabbed her pointing, poking finger, stepped away from her wrath. "You love me, so be with me. Don't let this get in the way."

"Be with you? You think I'm not trying to be with you? I don't want you to die, you asshole."

He stared at her, not sure he'd ever heard something so encouraging and disheartening at the same time.

She snorted and shook her head at him, setting her jaw. "It's your choice, Castle. You choose - be with me, or keep doing this and wind up like everyone else who's ever touched this case. Dead."

Be with me.

He took a long breath, tried to gather up the shreds of his dignity, his calm, his good sense.

Kate bit her lip and turned her head, scraped at her other cheek with the back of her hand. "I see," she whispered. She brushed past him so fast, it took him a moment to realizes she was going - going, leaving him-

"Wait. No. Kate-" He stumbled after her, caught her by the wrist before she could open the door. "Kate. Stop."

She wouldn't look at him. But she wasn't moving away either.

"It's not that simple," he said. "I wish it were."

She said nothing, didn't turn around. He stroked the inside of her wrist - he knew he was doing it to be persuasive, to seduce her; he knew it - and so did she. She jerked her hand away from his touch, crossed her arms over her chest, kept her back to him.

"Kate. Let me - at least listen. Please."

She turned her head, glanced at him over her shoulder, the strong and proud and stunning line of her profile like a punch in his gut. "But you don't say anything new, Castle. Why should I listen?"

"Here's something new," he said, feeling reckless and stupid and desperate. "Here's the truth. I'm afraid that if I drop this, if I don't figure out who had you shot, who murdered your mother, you'll never lay this case to rest. You'll never let it go, Kate, and I'll lose you. It's better that you're alive and not with me, than with me for a moment and then gone forever."

She jerked around, that tendon in her forehead pulsing.

He honestly had no idea what she'd say to that, because he knew and she knew too that he spoke the truth. She wouldn't let it go, couldn't. She'd wind up back in the same spot she was in the summer she got shot - staring down a sniper's rifle because she couldn't let it go. So what else was there to say?

Kate closed her eyes, struggled with something, and then opened them again to stare straight down into him, as if cutting through layers of years and defensive mechanisms and coping skills and bullshit that he'd buried himself in.

He was afraid she'd leave him. That's all. Not just that she'd die, yeah that, but he was just afraid, deeply afraid, that she'd get tired of dealing with him, his stuff, his need for her, his want, and then she'd just go. She'd just-

"You really are an idiot," she said softly.

He jerked his eyes up to meet hers, confused.

"How are those two things mutually exclusive, Castle? You solve this or I die? That's - that's crazy."

He set his jaw and shuffled back, unhappy with the tone of her voice, the way she looked at him like he was - he was an idiot.

"Look," she said suddenly. "You asked me to drop it. You came to me, Castle, and you told me to let it go for now. Can't you do the same for me?"

A split, a crack in their stalemate. Wasn't it? "Let it go . . . for now?"

She took a deep breath; that tendon was back to throbbing in her forehead. "For . . . now. Okay. For now."

He blinked at her, stunned. "That - is that - what did we just do?"

"I think we just extended our contract," she laughed. "For another year."

"Until the summer?" His lips quirked, but it didn't feel funny. "At which point we'll revisit the terms and open up negotiations."

The smile dropped off her face. "I don't - I don't want to do this, us, like that."

He sighed. "I don't either."

"Why can't - why can't you just not do this?" she whispered. "It's my mother, not yours. My-"

"May not be my mother, but my - my - you're mine. My detective. My muse. A whole lot of other things I can't yet claim, but I want to. I already have."

She gaped at him, then shook her head, closed her mouth. "I - okay. I see that. You've got just as much invested in this as I do."

That was - big. A real confession. It deserved an equal confession from him. "I don't want to lose you, Kate."

"You don't even have me, Castle."

He sucked in a breath, couldn't negate the truth of that no matter how much it hurt. "If I stop." He paused, tried to search for the words he needed, the words that would make her understand.

"If you stop," she prompted, sliding closer.

"Then what happens to that wall?" He lifted his eyes to hers, let the desolation shine through. The sense of doom that he carried with him every day over what he knew would be their future if he couldn't get this thing laid to rest. "What happens when some new piece of evidence crops up and you can't stop thinking about it? What happens when you're in your apartment staring at those shutters, making yourself an easy target, and you won't walk away no matter how I beg?"

She didn't respond at first, didn't try to rebuff him with the easy, That won't happen. She kept a careful, steady gaze on him and then nodded. "Okay. So, how about this? You get the power to veto. This one thing, this one - one issue between us. You get to tell me no."

He swallowed hard and stared at her. "I - I do?"

"If that happens, if I get - sucked down into it again, and you come to me, and you tell me we can't do this, you tell me it's too dangerous, then - then I won't do it."

"Unlike last time," he said, his voice heavy, remembering how she threw him out of her apartment, how she told him he'd only been treating her life like a playground and she was tired of it and she didn't want him involved anymore.

She bit her lip, gnawed at it, then nodded. "Unlike last time. I'm sorry."

He let out a slow breath, wondered if this fragile thing that burned the back of his throat was grief or hope. "I - you'll let me tell you to stop. You'll listen to me and you'll stop?"

"If I get to tell you to stop now, then, yeah Castle, you get to tell me to stop."

Oh. Oh, he hadn't seen it like that.

"Okay," he said in a rush, breathing past the choked up feeling in his throat. "Okay. I'll stop."

The agony dropped right off her face, the indecision, the fear - gone. Her eyes lit up, her whole face, her mouth stretching wide in a hesitating but blossoming smile. "Yeah?"

"Yeah." He nodded back, found that his own mouth was curving into a smile as well. "Yeah, if you - yeah."

She beamed at him, all beautiful eyes and her pink tongue touching her teeth and that mouth spread so wide and generous and inviting. "I love you," she said and surged up into him, pressed her smile to his, laughing, light, amazing.

"Kate," he groaned, wrapping his arms around her, catching her up, his heart burning.

"I love you," she said again, breathless, her mouth breaking from his so that she could bury her nose into his shoulder, her whole body embracing him, tight, so tight. "Oh, God."

"I can - do I have you now?" he whispered, pressing his lips at her cheek.

"Yes, yes," she murmured, laughed again, her breathing sigh out like a weightless and feathering thing, drifting up. "You've got me, Rick."