A/N: Another post-Hunt idea that wouldn't let go once Shazam12 gave me the first couple of words. Not sure how they'll handle Castle's dad on the show. But I was struck by the thought that Castle loves the pull of the new - the novel appeal of that shiny, new toy that feeds his continued, child-like need for novelty and excitement, and so that's what led me down this particular track.

Betrayal Is A Shiny Yellow Golden Thing

"Your father?" repeats Kate, dumbly, her eyes flicking back to the tall, white-haired stranger loitering by the aircraft steps.

"I know. Crazy, right?" says Castle, squeezing her hand and trying to draw her closer to the Gulfstream.

She watches an Immigration and Customs Enforcement official arrive to board the private plane, gloved hands gripping the hand rail, and she finds herself worrying that the man will wake the girls before they're ready. Worries that he might scare them - another male stranger suddenly appearing in their midst - after all that they've been through.

"Castle, your mom. She's waiting for you inside," she reminds him, tilting her head towards the terminal.

"This will just take a second. I really want him to meet you, Kate," he says, enthusiastically, tugging on her hand.

"Castle, your mother!" exclaims Kate, stopping him just feet away from where this stranger is standing - this unsettlingly familiar stranger who bears more than a passing resemblance to her lover.

If her lover were in his sixties.

And it's like looking at her future in some small way; at the man she hopes will be her future, time-lapsed, age-progressed into this rugged, kind-faced, but somehow worldlier version of the Richard Castle she knows. Though lately she wonders if there is in fact a lot more to her partner than she has yet seen - hidden depths that are starting to rise to the surface.

"Do you have…any idea what she's been through these last few days? Do you? What we've both been through? Because if you did you'd be running in there to give her a hug and let her know that you are okay, that Alexis is okay."

"This'll just take a second, I promise," he insists, failing to listen, to heed her clear warning.

"No!" exclaims Kate, startling when she hears the deep, throaty voice of this stranger who apparently shares DNA with her partner, as the man clears his throat.

"Castle, no," she sighs, exhausted, backing away from him, shaking her head, all the feelings she tried to stuff down inside until later, until the beauty of their reunion could be enjoyed, unsullied by how angry she is at him for taking off to play Rambo without her, rising up to spoil things.

"No?" he asks, reaching for her hand, clearly bewildered by her behavior, if the hurt she can see welling in his eyes is any indication.

He's reacting in typical Castle fashion to this, she realizes – to finding his father, if that's who this stranger really is, though the similarities between them make it hard to deny - like an eager child at the thrill of the new. He's like the Princess in the Grimm Brother's fairytale of the Frog Prince: besotted by his own shiny, golden ball. His own diu amissam pater familias - this long lost head of his family.

"Castle, your mom has been living a nightmare. Trying to hide it from me, sure. But even I know her well enough to see what this has cost her… And now you want to make her wait so you can…what? Introduce me to some stranger who says he's your father? What about Martha, Rick? Have you thought what this is going to do to her?"

"She'll be fine with it," he says dismissively, as if he's irked that she's ruining his fun. The big reveal he's been planning on the seven plus hours journey home. "She'll cope. Always does."

"Really? What makes you so sure?"

"I think I know my own mother, Beckett."

"Oh…oh, really?" she scoffs, walking backwards away from him. "Beckett now is it? Well, if you don't care about her feelings, I damn well do, and someone has to go prepare her for this…this ticking time bomb of souvenir you decided to bring back with you. I'll see you inside," she says coldly, turning to walk away with a shake of her head.

"Ms. Beckett…?"

The stranger's voice cuts through the chill breeze, the damp, marshy air, the rumble of airport life carrying on all around them, oblivious to this burgeoning family drama. And it arrests her on the spot; stops her from retreating any further. If Richard Castle can ask anything of her, almost anything these days, it seems this power may run like a seam of gold right through the family genes. Because she finds herself unable to resist the pull of request that nestles, as yet unvoiced, in this man's polite, but powerful deployment of her name.

She spins around to find…she doesn't even know what to call him, even inside her own head. Castle's what? Sperm donor? Biological father? Dad? His supposed father now standing between her and her partner, and how did he even…?

"I wanted to thank you," he says, a hint of a drawl she can't quite place layered through his accent.

"Th…thank me?" she stutters, stunned by his self-confidence.

Because there is no way he did not just hear their angry little exchange - her refusal to meet him and her overarching concern for and loyalty to Martha Rodgers.

"Yes. For teaching my son a thing or two about…"

"Your son?" blurts Kate, turning furious eyes on Castle.

She's really smarting for Martha, she tells herself. Indignant on the older woman's behalf, for all the work she put into raising her son alone, to turning him into the man he is today. No matter how eccentric and misguided her hand may have been in his life at times, she was there, there for him and is daughter. Unlike this…this fluke of male biology, this serendipitous accident of timing.

But if she's honest, she's actually a little angry on her own behalf too. Hurt that he has done this without her, no matter how accidental and unplanned – finding his father on some rogue-jaunt overseas. Because it scares her too - this gnawing feeling that he's morphing into someone else, moving on, growing without her. Castle is dependable, a constant in her life. He has been for the past five years. Even as an author, just a handsome face on the back of a dust jacket for years before that, his words were dependable, something she could reply on to take her out of herself, no matter how dark the days got. He's been her loyal puppy - waiting, patient, loving, always at her beck and call. But now he's striking out on his own it seems, and she doesn't like it: this role-reversal, this change in their dynamic, the new strength he seems to be exhibiting.

But then the stranger is speaking again, and she has to shut down her jealous, insecure, inner voice to listen to him.

"Mmm, tells me you taught him a helluva lot over the years. 'Bout strategy, negotiation, planning…survival. Said you're quite a sight to behold in an interrogation room too. Must say, I didn't believe him at first…but you're rapidly changing my mind, detective."

And fuck, where does this guy get off…?

"Does he now?" is all she can manage to force past her lips, until she looks at Castle, his disappointment that this meeting between his girlfriend and his father is evidently not going at all how he planned written all over his exhausted face.

And that's what finally does it: the disappointed, exhausted look on his face. The heartbreaking expression worn by this man who asks so little of her that she feels guilty possessing the knowledge alone of how much he holds himself back. All so that they can live at her emotionally stunted pace; moving forward to her heart's restrictive timetable.

And she realizes how well she knows him. She knows him and she owes him, and she…she just can't refuse him anymore.

So in the end, her love for Castle is what wins. Her heart twists at the shattered, gutted, brooding expression he wears like shackles. He's been without a father for over forty years, never talking about it, never complaining or using it to excuse his own, sometimes questionable, behavior. She's only been without the mother she had the good-fortune to know and love for fourteen, and she can't begin to understand how he might feel. How big this is for him. So maybe she needs to cut him some slack after all?

She looks from father to son once more, the resemblance growing stronger, more incontrovertible by the second, as a yellow-gold light begins to paint the scene in front of her with the warmth of the setting sun; the glory of another dying day.

She clears her throat, unclenches her fists, and releases her poor, tender lip from between her teeth.

"Kate," she says confidently, taking a step towards the white-haired stranger. "It's Kate," she repeats, more loudly, thrusting her hand out for him to shake, as he meets her gaze with a hesitant question of his own.

And when she catches Castle's eye, her heart somersaults in her chest at the gratitude and love she sees burning in his tired eyes. Light shines right out of him, a radiance aimed squarely at her, and it's like a beautiful rainbow materializing after a rainstorm – breathtaking, ethereal, but undeniable despite its transience. Witnessed by one is proof enough that it existed. It happened, she saw it, and that's all she needs to know. How fiercely he loves her, how important she is to him, the place she holds in his life now. She's a part of his future and his past, in a way that this man can never claim to be.

There is no competition to be found here, for her or for Martha.

"Yes, Kate. My name is Kate. It's a pleasure to meet you."

Yellow noun: the color of gold, butter, or ripe lemons. Commonly associated with sunshine, reason, optimism and pleasure, but also with envy, jealousy and betrayal. Yellow is related to the ego and our sense of self worth, to how we feel about ourselves and how we are perceived by others. The emotive symbolism conveyed by the color yellow includes dishonesty, cowardice, betrayal, jealousy, covetousness, deceit, illness, and hazardous.

Thoughts?