Grace is skipping around the apartment in a way she hasn't in weeks, the skirt of her dress whispering along her knees and the toes of her miniature ankle boots tapping along the wooden floors, and Kate huffs from her bedroom as the girl glides by.

"What has you in such a mood?" she chuckles, waiting for Grace to backtrack to the doorway, the coal grey skirt falling to rest against the warm fabric of her tights.

"I'm just excited for dinner," Grace quips, leaning against the frame of the door while Kate attempts to tame the curls of her hair, the strands rebelling, causing her to worry way too much about her appearance.

It was just an innocent dinner with the Castles, mostly for Grace's benefit, but she still tugged at the purple fabric of her favorite sweater, frowned at her reflection, and growled at the renegade curls of her hair.

"Momma, are you nervous?"

Kate lifts her gaze from the mirror on her closet door, swinging it to the little girl watching her with a look that is far too knowing for a seven year old.

"No, why would I be nervous?" she counters, giving up on her hair and stepping away from the closet, tucking the chain with her mother's ring beneath the neck of her sweater.

"Because Mr. Castle will be there," Grace answers with the corner of her mouth twitching, the beginnings of a smirk.

Kate rolls her eyes and lowers to sit on the edge of her bed, tug on her boots. "You're being silly."

"Am not," Grace denies, entering her mother's room and plopping down on the bed next to Kate, bouncing into her side. "He looks at you with starry eyes."

"He looks at everyone with starry eyes," Kate chuckles, well aware of Richard Castle's reputation.

Granted, she hadn't seen a hint of that man around his daughter last week when they had met amidst the post-Thanksgiving madness of the shopping center. But just because Castle could behave around his daughter, around Beckett and hers, didn't mean the jackass she saw in TV interviews and Page Six didn't exist, and she wouldn't subject herself to such a risk. No matter how he looked at her.

"Momma, when was the last time you were in love?"

Kate lifts her eyes to the ceiling, cursing Richard Castle for unintentionally inspiring these questions, this uncharacteristic train of thought in her daughter. The last thing she wanted was for Grace to begin fantasizing about her mother falling in love with the writer, to hope for them to become some big happy family, wanting something that could never happen.

She's simultaneously a mom and a homicide detective, in no way does she have time for a relationship, let alone with someone like Castle. Even if he could apparently make her daughter smile easier than anything – and anyone – else can.

"Grace, you do know Rick and I are only going to be friends, right? This isn't going to be a Disney movie," she warns and her kid huffs in exasperation.

"I know that," Grace states as if it's her mom who's being absolutely ridiculous, rolling her eyes and offering Kate a horrifying glimpse into the upcoming teenage years. "It was just a question."

"Questions always lead to more," Kate reminds her, sitting up and bumping her daughter's thin shoulder, watching her drop onto her back atop the bed, staring up at the ceiling and kicking her legs back and forth.

"I never want to fall in love," Grace proclaims. "I wanna be like Merida from Brave."

"Ah," Kate hums at the mention of the feisty redheaded princess from one of Grace's favorite movies. "Warrior princess then?"

"Yes," Grace agrees with relish, sitting up and adjusting her polka dot sweater across her torso. "I wanna be a badass like you-"

"Grace," she says sternly, earning a sigh of apology. "What have I told you?"

"Uncle Javi's the one who said-"

"Is Uncle Javi your mom?"

Grace pouts, dramatic and childish, refreshing. Kate's become so used to seeing her little girl acting so constantly grown up, bordering on too mature for a seven year old.

"No," she grumbles, hopping down from the bed as Kate rises, snagging her purse from the armchair near the bedroom door and shutting off the lights.

"Then no cursing. Or doing anything else he does."

Grace copies Kate and slips her coat on at the front door. "What about Uncle Ryan?"

A better example but-

"You're pushing it, kid."

A flicker of amusement dances along her daughter's lips, the closest thing to a smile Grace usually produces, and Kate brushes her thumb to her slightly raised cheek, nods towards the door.

"Now, come on. Don't want to be late," she murmurs and Grace walks through the door, waits in the hall while Kate locks up.

"But Momma?"

"Hmm?"

"You look really pretty."

Kate's mouth curves and she reaches forward to button the collar of Grace's coat.

"So do you, beautiful girl."

Richard Castle proves to be an amazing cook, filling her stomach with the best home-cooked meal she's had in ages.

She tries her best to cut back on the takeout for Grace's sake, to cook as much as she can, but at the precinct, especially during a rough case, she's more often than not stuck consuming the quickest options available. The homemade lasagna is a welcome change.

"You cook as good as my mom!" Grace informs Castle at the end of their meal and Kate blushes, shakes her head from her spot beside her daughter at the table.

"Grace-"

"Oh, really? You cook?" Castle questions across from her, impressed, and Beckett arches an eyebrow in reply.

"Yes, I cook. Whenever I'm home in time," she states, taking a slow sip of her water to wash down the final bite of her dinner. He had offered her wine, but she'd politely declined, unable to acquire a level of comfort when it came to drinking while her daughter was around, and she'd found it interesting that her choice had influenced his, had him putting the wine back on the rack.

"Right, because you're a detective," he relishes and Kate rolls her eyes, unable to comprehend his fascination with her profession.

Will had been the only man to ever accept her work, appreciating the level of understanding it had built between them from the beginning, but others had cringed at the job description. Castle, though, had been the first to practically glow with excitement when she'd answered his inquiry about her career during their dinner last week.

"Maybe Mr. Castle and Alexis can have dinner at our apartment someday," Grace suggests, a conflicting blend of shyness and hope flashing in her eyes as she casts them to Kate.

"Grace, you can call me Rick, remember?" Castle prompts, his voice kind, encouraging, and Grace nods sheepishly in reply. "Also, Alexis and I would love to have dinner at your apartment sometime, as long as it's okay with your mom."

"Depends on my work schedule, but we'll see," Kate answers with a small smile for her daughter and his, another eye roll for Castle who's practically preening at the idea of seeing her place, but Alexis is too quiet at the other end of the table, sitting across from Grace and pushing around the remainder of her food with her fork.

"Did you guys want dessert? Alexis and I made our famous cheesecake," Castle boasts, sneaking a glance to his daughter, and she smiles in response, but her heart's not in it and Beckett can see the worry that blooms in his eyes, spreads through the lines along his face, making him look so much older. "Want to help me serve, Pumpkin?"

"Is it okay if I go to my room, Dad? I'm not feeling so good," Alexis murmurs, worsening Castle's concern, but he nods.

"Of course. Here, let me just get this and I'll-"

"Grace and I can head out if you need-"

"No, no, it's fine," Alexis promises them all. "Just a long day at school and I'm really tired, but it was so good to see you guys again."

The smile Alexis offers the Becketts is genuine but strained, cracking at the edges, and Kate's gut churns with worry, fear that her and Grace's presence tonight wasn't such a good idea after all.

"Okay," Castle agrees reluctantly as Alexis rises to stand. "I'll be up to check on you in a few minutes then."

"Thanks, Dad," Alexis murmurs, walking around the table, pausing to give Grace a hug goodbye just as she had hugged the girl in greeting earlier, and starts for the stairs.

Kate stands to follow, appeasing Castle's questioning look and Grace's confused glance with a lift of her hand, hoping he'll trust her with his kid, trust that she would never say anything to upset Alexis; she only wants to assure her.

"Hey, Lex?"

Alexis stops on the first step, her eyes curious as she turns back to witness Kate approaching.

"Yes, Kate?"

"I just – I wanted to make sure you were comfortable with us being here," Beckett gets out, shifting a little awkwardly in front of the teenager who behaves so much more like a young adult, who makes her feel as if she's catching a glimpse of whom Grace could grow to mirror. "I know we're just two people you met in a store a week ago and-"

"Oh, you think… you think I don't like you and Grace?" Alexis asks incredulously, tilting her head to the side as if trying to study Kate for confirmation. "I'm not uncomfortable. I know Grace is nearly half my age, but sometimes she seems just as smart as some of my friends. And you're great too, Kate. I was excited for you guys to join us for dinner again tonight."

Beckett steps closer, checking over her shoulder and noticing Rick and Grace in the kitchen, Castle showing Grace how to transfer a slice of cake onto a plate. "Then… is everything okay?"

Alexis shrugs and it doesn't take being a detective to know that his daughter isn't having the greatest day after all.

"My dad says I stress too much over grades," Alexis sighs after Kate risks a few moments of silence to wait her out, allow her the chance to talk about it, and Beckett is almost surprised that she takes it. Almost. "But today, I got a B on a test I studied really hard for in science, and then my best friend, Paige, cancelled our plans for the third time this week because some boy asked her out, and when I got home, my mom called and said she wasn't going to be stopping by the week before Christmas after all and that I might see her on New Year's, but I honestly hope she cancels on me for that too. Meredith just makes things harder," Alexis mutters, scraping at her bangs, blinking away the glimmer in her eyes.

"I'm sorry, Alexis," Kate sighs, lifting her hand to squeeze the girl's arm, brushing her thumb to her elbow when her blue eyes begin to blur and she has to purse her lips.

"I'm okay," she declares softly. "I'll make up the B with extra credit and I can hang out with Paige some other time. And my mom… Meredith," she tries to correct herself, and it scrapes at Kate's heart a little to watch the girl in front of her attempting to sever the tie of mother and daughter. "She does this all the time, ever since I can remember, it shouldn't – there's no reason to be upset."

"Just because you're used to a person's behavior, doesn't mean you ever start accepting it as okay, Alexis," Kate reasons, lowering her voice to the tone she uses for victims of lost loved ones, but refusing to treat his daughter as if she is one. "It's okay to be disappointed in your mom, to be hurt by her not showing up when she told you she would."

"But I don't want to be," Alexis sighs, swallowing down her tears. "I don't want it to bother me."

Kate releases her arm, purses her lips, and nods her understanding. "I know, but that's part of being human, you know? You love your mom, just as I have no doubts that she loves you, even if she isn't the greatest at showing it. And it's okay to be upset with her over this."

Alexis seems reluctant to believe her, frowning down at her fidgeting fingers.

"You know what might help a bit?" Kate muses, earning the quirk of Alexis's brow. "Your dad's cheesecake."

A laugh slips out of her, soft and surprised, but Alexis is nodding, descending from the foot of the stairs to step down beside Kate.

"Can't argue with that, but Kate?"

"Yeah?"

Alexis hesitates, but wraps her arms briefly around Kate's waist, a quick squeeze of an embrace before she lets go, smiles shyly.

"Thanks."

"Anytime." Kate returns the smile, patting Alexis's shoulder and pushing her towards the dining room table where Grace is enjoying her dessert while Castle picks at his, pretends that he hasn't been sneaking glances and trying to crane his neck towards the direction of their conversation for the last five minutes.

Alexis grabs two plates of cheesecake from the island, hands one to Kate and reclaims her spot next to her dad, explaining that she wanted some dessert after all. Rick lifts his gaze to her with gratitude while she settles down across from him, nudging his foot beneath the table and humming around her forkful of scrumptious cheesecake.

"This is incredible, Castle," she praises, her approval of his baking earning an eager nod from Grace at her side.

"You keep showing up and I'll give you the recipe," Castle bargains, returning the bump of her foot with the brush of his own, and Kate hesitates before finally crossing her legs to avoid an inadvertent game of footsie beneath the table.

"What if I keep showing up and you just keep making the cheesecake for me?" she counters, hearing Grace giggle around her dessert. "Grace. Don't-"

"Mommy can't bake cheesecake," Grace reveals, dodging the stretch of Kate's palm trying to cover her usually quiet mouth. "She always burns it."

"One time-"

"Was all it took for the fire department to come," Grace reminds her with a narrowed look that has Alexis smothering a laugh while Rick expresses his amusement at her expense without shame.

"Don't get cocky, Dad," Alexis warns. "Or I'll tell them about the turkey incident of 2010."

Rick's jaw snaps shut, but Kate leans forward in interest, Grace mimicking her.

"Turkey incident?" she repeats, one of her eyebrows arching. "Do tell, Alexis."

"No, no, cheesecake," Rick cuts in. "We were talking about cheesecake."

"Some other time," Alexis promises with a wink while her father gasps in horror, dropping his fork to his plate as he turns in his seat.

"You would betray your father like this?"

"Betrayal? More like evening the playing field," Kate points out, scooping another bite of cheesecake into her mouth, grinning smugly around the rich flavor.

"Truce? As long as you're here, I'll make you as many cheesecakes as your heart desires, Kate Beckett," he promises and Grace reaches forward to shake his hand on her mother's behalf.

"Deal," her daughter replies seriously and Kate huffs a laugh.

"Looks like you'll be around for an indefinite amount of time," Rick surmises, like he's the real winner here, and Kate shrugs.

Might as well embrace this odd arrangement blooming into existence between the four of them. For Grace's sake.

She smiles into her next bite of cheesecake. "Apparently so."

"You helped my kid earlier." Kate lifts her gaze to the man approaching her in his kitchen, his eyes falling to the sink, where she's washing off his dishes and loading them into the washer. "And now you're doing my dishes."

"I tried and I am," she nods, rinsing one of the last plates from dessert and inserting it into a free space on the rack. "Grace isn't glued to Alexis's side, is she?"

"Nah, Alexis is letting her look through her book collection," Castle assures her, taking a fork from her fingers. "Stop doing my dishes, you're a guest."

"Who can help clean up afterwards," she argues, stealing the silverware back, rinsing it off and dropping it in next, but he's still staring at her, a little awed and a lot appreciative. "And you helped my kid too so stop looking at me like that."

"Like what?" he questions, fishing, and Kate huffs, unwilling to answer that. "Like I find you extraordinary? Because I kinda can't help that."

Her fingers pause, waver over the sink, and Beckett purses her lips. "You don't know me well enough to say things like that."

"I know you're a hardworking mom who's also a badass detective, according to Grace, and doing her best to make the little girl upstairs as happy as she can possibly be," he lists, causing her skin to flush and her heart to skitter, her nerves to flare. "You're smart, clever, and I won't even begin to comment on your appearance because-"

"Castle." He stops, clamping his mouth shut, and she closes her eyes for a moment, searches for the words that won't come, that she doesn't want to say but are necessary. "I've known you for a week and I could say just as many positive things about you, but I just – I think it would be better if we remained friends. Only friends."

His expression remains neutral, blank, but the firelight in his eyes has failed to die.

"For the sake of our kids?"

"Yes." And for the sake of her heart, which has taken one too many beatings over the last fifteen years, since a detective had shown up on their doorstep, shattered it to pieces; she's unsure it could sustain another blow.

"Even if you feel the same connection I do?" he challenges, nothing giving except the upwards curve of his eyebrow, and Kate blows out a breath, because yeah, she may feel it too, may feel sparks travel up from the whorls of her fingertips, through the bones of her arms and setting her bloodstream aflame, any time he offhandedly touches her, any time he's close by.

"Even so," she nods, bracing her hands on the edge of the sink. "I can't let my daughter get hurt again, Rick. You – she likes you, for some reason."

He huffs in offense, but it breaks the tension, just like she'd hoped it would, and she grins up at him.

"Grace hasn't been able to smile quite as much, to laugh as much as she used to, since her dad decided she wasn't worth the time anymore. It's been hard enough for her having parents that were never together, but the day he decided he was done trying for her…" Kate squares her jaw, unable to help the anger that blooms every time she thinks about it. "I can't let anyone hurt her like that again. I don't want her to think that's all anyone will ever do."

"I know, I know the feeling," he murmurs, so much understanding in his eyes, she could practically weep with the relief of witnessing it. "And I don't want to do that, Kate. To either of you. We have the same goals, to protect our kids' hearts."

"Yeah," Kate sighs, so grateful he gets it, that someone can finally grasp where she's coming from.

"Doesn't mean I'm going to give up hope on being more than just your friend one day, Kate."

Gratitude drains from her system, exasperation taking its place, and she sighs her defeat. Fine, let him think whatever he wants, believe that some future romance will develop; he'll see soon enough that it's a fruitless endeavor with her.

She's a difficult person to love.

"I admire your persistence," she concedes wryly, trying to ignore the way his smile has her heart accelerating. "Just don't expect any Christmas miracles on that front."

"Shh, stop ruining my story with your depressing logic, Scrooge."

She smacks him in the arm with a dishtowel, the laughter bubbling in her throat, almost making her wish she could defy her own rules.