"Harper Grace Castle, what exactly do you think you're doing?"

The girl freezes, her eyes shooting up to catch her mother staring at her in the mirror.

The lipstick drops from her hand, clatters loudly on the counter.

"I was putting pretty on like you?" It's a not a question, but the way her voice squeaks at the end makes it sound like one.

Kate bites the inside of her cheek to contain the grin threatening to spill across her face. The five year old looks absolutely ridiculous, blush smeared all over her cheeks, her forehead, her chin, all shades of eyeshadow above and around her eyes –

"Whose makeup is that?" Kate Beckett has never owned anything in that shade of pink.

The girl visibly gulps. "Lexi's?" It's also not an actual question, but the girl is so nervous she can't seem to make statements.

It must be some collection Alexis left behind, probably tossed haphazardly in a cabinet somewhere.

The girl does live in her old room.

Kate sighs and steps into the bathroom.

"How did you even get up – oh." At that moment she sees the step stool – meant exclusively for reaching the sink to wash hands, thank you very much – and tracks the way her daughter must have wiggled herself up so she could sit entirely on the countertop. "What have we told you about climbing?"

"That it's dangerous and I'm not apposed to do it?"

"That's right. No climbing. Certainly no stealing your sister's makeup and making a mess everywhere."

"I sorry, Mommy." And, oh, if the mommy and the pout don't just kill her. Even though she knows her daughter is totally playing her with the baby talk and the tremor in her lip.

Dramatic, just like her daddy.

"Okay, baby. Come here." Kate puts her arms out and Harper smiles, practically falling forward against her. She sits her on the ledge and keeps the girl there with an arm at her waist as she reaches around for the makeup removing wipes.

She wipes it all off (it takes five wipes to completely finish the job) and then puts the girl softly on the floor.

She bends at the knees to get on the kid's level.

"We won't be doing this again, will we, Harper Grace?"

"Oh, but Mommy, can't I when I big? Like you and Lexi? I want to be pretty like you, Mommy. I really do."

The intentness of her daughter's eyes, the clear sincerity of the statement, makes Kate's heart clench.

Always so serious, this one.

Nothing like her sister, the seven year old who is always so bright and cheery, so free-spirited.

Castle is constantly reassuring her that kids just have different personalities, that it's no one's fault – that it's not even a problem that requires the assigning of faults – that one kid is more reserved than the other.

But all she can see is that they have one daughter with Castle's spirit, and one with hers. Like it is entirely her fault.

She breathes through it, brushes the almost inexplicably light hair (seriously, where did that blonde come from?) out of her younger daughter's face.

"Baby, you're beautiful just like this. So very pretty," she tells her softly.

The girl ducks her head, blushing, and Kate bites her lip, wonders how to reach inside her tiny little soul and draw her out.

Well, she does know what works for her, what's made all that love and joy bubble above and beyond anything she thought she could ever feel.

"I know. Let's go find Daddy and see what he's up to."

The girl lights up at that and, as soon as Kate stands, sticks her arms up at her.

"Yeah, yeah," Kate mumbles as she lifts her, settles the girl on her hip. Five is a little old for this, but Kate can't help herself when she pouts. And she really is so slight a thing, so very easy to carry around.

She walks out of the bathroom and down the stairs, finds Castle sitting at the table with their older – middle daughter, because Alexis is really so much a part of this different, newer family – their expressions animated as they go back and forth about god only knows what.

He stops and turns to her as she reaches the bottom stair, and the way his whole face breaks out in a wide smile, his eyes so bright and warm and loving, still, years and years later, sends butterflies erupting in her stomach.

"Hey there, my other girls. Please come help explain to Jilly Bean that Harry Potter is sooooo much better than the silly magician series she's been reading."

Jillian stops giggling at that and glares harshly at her father.

Oh, and isn't that just like looking in a mirror.

"My name. Is not. Jilly Bean. Or Jilly. Or Jill." She has her arms crossed tightly against her chest, her whole posture defensive. "It's Jillian Skye and you know that, Dad."

Kate's hand flies to her mouth in an attempt to stifle the laugh that wants out at that.

Castle does a better job of keeping it together, his face serious and stern. "And you know not to speak to me that way, little miss." He pauses, stares back at the girl, waits for her to deflate.

Which she does, quickly, under his gaze.

Never wants to disappoint her daddy.

"But, I will try to remember to use your big girl name," Castle finally concedes, and Jillian looks so thrilled with him that Kate can't keep the laugh back this time.

He turns to her again, gives her that crooked smile and beckons her into the room.

She sits, Harper still in her arms, and joins in on the Great Magical Book Debate, as it has been dubbed by all parties.

For a while, Harper just watches it happen, her eyes going back and forth as the three of them discuss the issue as though it is the most serious thing in the world (and, by the looks of it, Jillian seems to think it is). But the younger girl is quiet in Kate's arms, and it unsettles her all over again.

So she jostles the girl, blows a loud raspberry at her neck. Harper breaks out into breathless giggles and Kate feels her chest ease.

"I know, I know. Harper would rather talk about Fancy Nancy. Isn't that right, my girl?" Castle says at exactly that moment, sensing Kate's worry.

Harper catches her breath, stops the giggling, but her smile is bright and happy now that she can join in.

"Oh, Daddy, she is just the best. I love her so much."

And Kate does relax a little, throws Castle a thankful smile for it.

The wide-eyed sincerity, the fierceness, isn't quite so bad when it's channeled into something as wonderful as books.

Ten years later, Kate happens upon her daughter in a similar position; perched on the bathroom counter, makeup strewn about, her brow furrowed in concentration.

Only this time, the girl is doing it for real, applying dark shadow and even darker eyeliner, making her dark eyes seem bigger, richer, deeper, especially against the backdrop of the soft yellow of her hair.

Castle would hate this. He does hate it. But he's long given up trying to stop the girl from doing it, has discovered that his way of doing things, of trying to connect with the girl – loud and rambunctious, alternately silly and demanding – doesn't work.

She knows that it makes him feel so helpless, so disconnected, especially in comparison to his relationships with Alexis and Jillian.

Kate is constantly reassuring him that he's a good dad, that, like he told her all those years ago, their children are all different, show their love and feel things in different ways.

In reality, she's trying to reassure herself of that, too.

Taking a deep, fortifying breath, she steps forward, leans against the door frame – doesn't dare barge in on the girl – and watches for the moment it takes for Harper to see her.

Kate flashes her a quick smile. "Going somewhere?" She tries to keep her voice light, even though she is desperate for information from this oh so quiet teenager of hers.

"Out," the girl replies simply, her stock response.

Kate sighs and steps all the way in, reaches out to run her fingers over the girl's hair, a tenuous connection made even more so by the tight braid she's made, not a piece out of place. As though she needs the control wherever she can find it.

The girl's eyes close briefly, allowing herself a moment to absorb her mother's touch. When she opens them again, she shakes her head, effectively dislodging Kate's hand.

"Harper Grace, you know I love you, baby." She doesn't finish the sentence, just lets it hang there like so much else.

I love you and I wish you would just talk to me. I'd love you through whatever this is.

The girl seems to hear those words anyway, finds a tight smile. "I know, mom. Me too."

It's the closest she's coming to saying it in a long time, and Kate has to fight to not make a big deal of it.

So she leans over and drops a soft kiss to the crown of her younger daughter's head, and walks back out.

She's pulled out of a deep sleep that night by a series of sharp, insistent taps on her arm. She startles awake, already half into panic mode with the unease she felt at watching Harper leave earlier that evening, the twisting in her gut she felt when the girl hadn't returned by the time she passed out at midnight.

But there are those dark, rich eyes staring at her, her long blonde hair now out of the braid and cascading over her shoulders, blocking out most of the girl's red-rimmed lids.

Wait. Red-rimmed? The girl never cries.

Kate sits up and reaches for her, but she backs away.

"Not here," Harper whispers, nodding towards her sleeping father.

Kate nods and follows her out and upstairs into her room.

Harper sits on the bed, backing herself into the corner and tilting her head up on the wall, staring at the glow-in-the-dark stars she let her sister put on the ceiling so long ago.

Kate sits at the edge of the bed and waits for the girl to start.

"His name is Mike."

And then the girl spends the rest of the night spilling her guts, revealing secrets and tender teenage love, backstabbing girls and boys asking for more than she wants to give.

By dawn, Harper's head is in Kate's lap, obviously exhausted – whether it's from the actual problems, from keeping it all so tightly locked inside her, or from finally letting it all out, Kate isn't sure.

All she knows is that she is so grateful for it.

When Kate finally slips back into bed, she's surprised to find Castle awake, sitting up.

"Hey," she whispers, somehow still needing the quiet and solitude of the night.

He smiles at her softly. "You're a good mom, Kate Castle."

And for once, she really believes it.