The sixth and last chapter is dedicated to JustAWriterWannaBe, who has been even more enthusiastic than me about this crossover, and that's saying something.

She was right, of course. He knew she would be, but as Rick follows Kate out of the loft he's having difficulty focusing on anything other than the way the gold material clings to her curves and drips over her soft skin. She's already calling the elevator by the time he finds his keys to lock up.

It's almost pointless to ask, and yet she does anyway. "You coming, Castle?" He stalks towards her, a feral growl emanating from his chest.

"You are a tease, Katherine Beckett," he tells her as he steps into the elevator with her. She smiles slyly in reply and loops her arm into the crook of his elbow.

"Hi ho, gang!" Kermit calls out as they exit the limo that Castle had laid on, all seven of them in tuxedos and beautiful dresses, sliding out gracefully to find a welcoming committee at the end of the red carpet. "Are we all here?" He meets them at the kerb and seems to be counting them and coming up one short.

The captain, wearing a demure dusky grey dress paired with a glitzy red shawl, steps forward, "Mr Gates was unable to attend at such short notice, but wanted me to pass on his thanks for the kind invitation." She smiles at Kermit who gave a happy shrug.

"That's a shame, but there's a waiting list so we can give his ticket to the person at the top." He adjusts his bowtie, looking dapper in his tuxedo, before sweeping his arm to his side to begin introducing his friends to them. "We wanted to welcome you all as special guests for the hard work you've all done the last few days for our friend, Allan, so here are your hosts for the evening."

Kermit seems to be about to send Gates off first, but Sweetums rushes past and engulfs Esposito in a crushing, furry hug. Javi raises his arms to steady himself against the eight-feet-high onslaught, "Woah! Easy, bro! Easy!"

"Ah, Detective Esposito, sorry, this is Sweetums, he does like hugs..."

"Yeah, I got that, Kermit, thanks." Sweetums half-relinquishes Esposito before he leads the detective off down the red carpet towards the theatre with an arm over his shoulder.

Castle waves to Rizzo who is wearing the biggest grin you could ever see on a rat. but Scooter is trying to get Kermit's attention, "Hey, boss? Boss?"

"Uh, yeah, Scooter?"

"We need to hurry this along a bit, curtain up is in fifteen."

"Oh, right, thanks!" Kermit turns back to the humans and quickly rattles off the hosting partners. "Captain Gates, you're with Animal," Animal flutters his eyelashes at her, and though he doesn't notice the raised eyebrow, her genuine smile and light fingers tickling behind his ear keep him calm and passive all the way to the foyer.

"Detective Ryan, you have Scooter, and Mrs Ryan? Walter will look after you, anything you need, just ask."

"Yeah, just ask!" Walter eagerly repeats and Jenny smiles sweetly at them both in thanks, though she is reluctant to relinquish her husband's supportive arm with barely days before their baby is due.

"Dr Parish, it's great to see you, you look simply radiant," Kermit beams at the medical examiner in her deep blue gown embellished with tiny diamantés that make the material shimmer.

"Well that's the nicest compliment I've had all evening. Could you teach Javier some lines?" Rick and Kate share a grin without Lanie seeing them, while Kermit continues.

Fozzie Bear will-..." Kermit begins, cut off by Fozzie's greeting.

"Wakka wakka wakka! Say, I know a whole load of 'doctor doctor' jokes, do you wanna hear one?" Lanie can barely reply before he begins as they head into the theatre.

"So Rizzo's with me, and Kate's with you, right?" Castle turns to Kermit with a smile, but his bubble is swiftly burst by the arrival of a certain porcine diva, in the most ghastly magenta silk and fuchsia taffeta monstrosity of a dress that the world has ever seen.

"Oh Rich-ard! Here you are, at last!" Castle blindly grabs for Beckett, grasping her wrist in a vice-like grip that has her retaliating with a pinch to his arm. "We have so much to talk about, mon amour."

Rick gulps so loudly that Kate can hear him swallow over the noise of the Broadway crowd. She leans in to murmur in his ear, "You got this, Castle. I'll make it up to you later."

He turns his head quickly, whispering harshly, "Promise?" She tilts her head and gives him a nod, flicking her fiery gaze from his eyes to his lips and back again before she sees him steel himself for the oncoming storm. He turns his attention back to the new arrival, "Miss Piggy, what a wonderful surprise!"

"I've got to head backstage now, I'll see you at the after-party!" Kermit waves and races off to the stage door to avoid being held up on his way.

"Detective Beckett? Shall we?" Kate smiles at Rizzo, for putting on such a suave and gentlemanly air, and he trots along beside her towards the theatre. She ambles slowly, keeping the same pace as Rick and Miss Piggy a few feet behind her. Just in case.

Miss Piggy is putting on a voice that would melt butter, smooth and sultry, with a slight squeak, "So, tell me Rich-ard, now that Natalie Rhodes is too busy for the next Nikki Heat movie, I think moi would make a good replacement, wouldn't you agree?"

Rick schools his features immediately, plastering on his camera-ready smile as they move into the photographers' corner. "Well Miss Piggy, you'd have to talk to Detective Beckett about that."

"Oh? Why would moi have to talk to Detective Beckett? What does she have to do with it?"

He turns to her, waiting until he has her attention and the last of the camera flashes trigger, "Because she's the real Nikki Heat." He hears Beckett's snort of laughter from just inside the open theatre door and makes his way straight over to her hiding place behind a pillar.

They both hear Miss Piggy's stunned and slightly delayed reaction, her frustration palpable even in the single syllable, "WHAT?!"

"Hey Dad!" Alexis turns and sees Castle just as he slips through the foyer doors. She waves to him and Kate and begins to make her way over to them, dragging Pi with her.

"Hi Alexis, you look great pumpkin," Rick smiles warmly at his daughter before he turns to her boyfriend, the smile fading from his eyes. "Pi. You scrub up pretty well." Pi deflates slightly and out of sight Beckett taps Castle angrily where her hand had been resting on his shoulder blade.

"Very dashing, Pi," Kate graces him with a bright smile, and Pi grins back, Alexis giving Kate a grateful look of relief.

A bell rings to signal there are five more minutes before the curtain goes up, so they make their way into the auditorium. Rick and Alexis lead the way, while Pi offers Kate his elbow. "Where are your seats, Pi?"

He fishes the tickets out from his jacket, and replies, "We're in the stalls on row 'J', Mrs C-to-be!"

Alexis turns to join in the conversation, "Yeah, I don't like to be in the lights, it's better for Gram if she can't see us."

Kate hums in reply with a small smile at Alexis' thoughtfulness. She reaches to smooth her palm over Rick's ribs to get his attention. "Where are we?"

"I don't know, I never got a ticket. Did you?" She shakes her head.

"Hey Detective Beckett? Mr Castle?" Their heads turn in unison to the voice of Rizzo. "There you are, come on with me to your seats!" They say bye to Alexis and Pi to follow their host into the house. "I hope you like sitting on the front row!"

"We're on the front row?" Rizzo turns to them both with an air of disbelief that they could be speaking together but with such different tones to their voices, one excited and the other wary.

Rick frowns, "Don't you like sitting on the front row?"

"Well, Alexis just said it's better for Martha if she can't see us."

"Oh, it'll be okay, front row is below her eye line, so unless she looks down on purpose she won't see us. And even if she does, she won't mind."

"So why did Alexis say it like it was on pain of death?"

"Here we are!" Rizzo cuts in, and Rick shrugs with a smile.

"I'll let Mother tell you later." He guides her to sit first, taking the end of the row for himself. They wave to the boys, Lanie, and Jenny, and Gates nods at them both in acknowledgement as the lights go down and Dr Teeth and the Electric Mayhem strike up the first notes of the opening number.

"And so the curtain swooshed down right on top of me, I was so distracted by Alexis popping up on the fourth row back I just never saw it coming until it was too late!" Kate was laughing hard, champagne glass in one hand, clutching Martha's arm with the other. "Ever since then, she refuses to sit any closer than row 'H', no matter how many times I tell her it was just the unpredictable timing, and she was only three, well..." Martha shrugs and waves with her martini.

Castle is by the bar with Esposito and Lanie, having sent the Ryans home in a town car almost straight away after the show ended, watching his fiancée from afar with the wisp of a smile across his face. "Hey! Bro! You with us, man?" He turns his attention back to the couple with him, both aware his mind was elsewhere.

"Sorry 'Sito, I was uh-..." He still has the good grace to look a little sheepish at being caught staring at Kate, even if everyone knows they are head over heels in love with each other.

"Yeah, yeah, mooning over Beckett, we know... I said, what was your favourite bit?"

"Oh, undoubtedly Ryan being taken onto the stage by the penguins. I don't think they realised what they were in for, getting the tie tying terror of the Twelfth up there for a sketch about wardrobe malfunctions..." They all laughed anew at the memory of Kevin doing up every penguin's tie with a different knot and none of them being able to undo them again during their costume change for the final number, the bright fluorescent yellows and oranges clashing horribly with the Christmassy reds and greens of the other colour scheme.

Captain Gates takes her leave of Kermit and joins the trio at the bar, gracing Rick with a smile, "Thank you for the ride here this evening, Mr Castle."

"You're welcome, sir. Would you like another drink?" He waves to get the attention of the barkeeper, but she shakes her head.

"No, thank you, some of us still have work tomorrow."

Rick smiles, "Can I call a town car for you then?"

She seems almost surprised, "Mr Castle, that's very kind of you, I'd appreciate it." He whips his phone out of his pocket and has the car on its way within seconds.

"Should be out front in a few minutes, Captain."

She nods her thanks and says goodbye, "And if I don't see you, a Merry Christmas, and a Happy New Year to you all." She passes Beckett on her way out, calling a cheery, "See you tomorrow, Detective," that has Kate wandering over to the bar looking slightly perplexed.

"Was that... Gates in a good mood?" She looks back over her shoulder again, as if she still can't believe it.

"It's Christmas, girl, makes everyone crazy," Lanie sasses.

"Ooh, I bet it's because her mother-in-law's not visiting this year!" Rick exclaims and they all laugh. The crowd is starting to thin out now, and Castle gets his phone out again to call a couple more town cars for Lanie and Javi, and his mother, Alexis and Pi. They all chat about their plans for the next couple of days until the cars arrive and take them all away, leaving Castle and Beckett in the foyer of the theatre.

"And how exactly are we getting home, Castle?"

"Well Detective Beckett, I'm glad you asked..." He stands behind her, broad chest to her slender back, and slowly rubs his hand up her arm to her exposed shoulder, fingers tripping across her collarbone. "You see, I have plans involving you, that limousine, and this dress you've been torturing me with all night."

Without missing a beat, she turns in his embrace and wraps her arms around his waist. "Really? Wouldn't it be better to travel by map?"

He grins, "Of course it would, we'd be able to go straight from here to our bedroom without any waiting around for a stupid limo!"

"Hold on one second..." She waves at Kermit and he points to a large map of New York on the wall by the ticket booths, giving her a thumbs up. She saunters over, pulling Rick along by his fingertips with a mischievous grin, "Come on, Castle. Let's test that bedroom theory of yours, shall we?"

Merry Christmas to all, and to all a good night!