A/N - Just a quick one-shot fic inspired by my own emotions after watching the latest Underworld :) Enjoy and please review!

Kate Beckett sits in a dark theater, empty popcorn bag at her feet and the credits rolling on the screen while Amy Lee belts out lyrics over a sinfully intense track remix. Tonight is one of those rare moments when Kate spoils herself with a guilty pleasure. The latest installment of Underworld has just finished and Kate lets inspired emotions wash over here while the crowd shuffles towards the exits. As the song ends, she rises from her seat in the back, stretching her amped muscles and relishing the feel of those endorphins running through her body. There is just something about these movies that makes you want to go have sex and kill something…they play to that ancient power center inside all of us. Luckily, the vast majority of society today plays by a more civilized code and those individuals that still function by their basic instincts have to answer to her. She has had more than her fair share of killing but the sex has been absent for a while. She debates going by the precinct to burn off the sudden and delicious sexual energy with someone willing to spar but settles for taking the long way home since there is no one in the world she wants to be with other than Castle and that just isn't an option yet. She had gone to a theater farther away than normal to avoid running into anyone she knew and figures walking through some of the seedier parts of town to get home again should be enough to raise her heart rate. At least, that's what she hopes.

As Kate walks, she lets her mind flow free. It wanders from topic to topic everything from the moon to her mom. Castle makes frequent appearances and after watching Kate Beckinsale strut around in tight leather with automatic hand guns, his appearances tend to involve nudity. Oh man, I need to find a distraction! She walks a little faster, feeling her pulse jump up a few beats per minute. Her mind jumps back to Kate Beckinsale and sticks. What is it about her that her mind is focusing on? Absentmindedly she stops in the middle of the side walk and shuts her eyes tight trying to bring back the memory that is apparently so tied to the actress. The moment flashes across the inside of her eyes lids and she remembers a short conversation with Castle. Of course, it just HAD to be a conversation with Castle. Not quite the distraction I was hoping for. Kate recalls the brief exchange from months ago regarding who would play "her" in the movie version of Heat Wave.

"We can call you K-Becks!" He posited excitedly at the time. That clearly wasn't who ended up with the part though he doesn't seem disappointed with that actress anymore either. She scowls at the memory of his reaction to Natalie in costume. Honestly, Kate hates that she get jealous when it comes to Castle but it's hardly in her control anymore these days. Kate keeps walking but something shiny sparkles in the corner of her eye. Kate slows and turns to look in the store window. A devilish grin creeps across her face. Well two can play the costume game.

~Castle's Halloween Bash 2012~

Halloween night has finally arrived. Castle fidgets excitedly as the first guests make their appearances. He has some deliciously horrible surprises planned for the evening's festivities. It doesn't take long for the party to hit full swing and Rick finds himself quite busy making the rounds though his eyes keep searching for his favorite Detective. A few times, he asks Ryan and Esposito if she is coming but they just give him vague shoulder shrugs. He suspects they know something he doesn't. Finally, Rick gets the chance to settle into a drink of his own, a pleasant buzz hitting him quickly. He wanders back over to his other two favorite detectives (though favorites for very different reasons obviously) who appear to be deep in conversation about another guest he can't see from his angle. He walks up behind them quietly and drops into their discussion.

"Yeah, but don't you think it's a little weird to show up as your own movie character? I mean come on, be a little creative."

"Who ya talking 'bout?" Both gentlemen jump slightly at the sudden intrusion but turn slightly to invite Castle into the circle.

"Kate Beckinsale over there." Espositio points towards a tall, slim, leggy brunette dressed in a skin tight, shiny black latex suit with leather corset and a stylish variation of combat boots.

"Dude, you didn't tell us she was going to be here. She is totally hot, even if she is dressed as her own Underworld character." Castle snaps out of his lusty daze and looks at Ryan in confusion.

"Wait a second, I didn't invite her."

"Well then, who's that?" Ryan and Esposito share a knowing glance, trying desperately to hide their smiles. Castle shrugs and brings his drink towards his mouth just as the mysterious woman turns around. It's Kate, not Beckinsale, but HIS Kate. The sexiest version of his Kate he has ever seen. Holy…shit….his mind mumbles to itself before completely melting into sinful oblivion. The glass slips from his hand as Kate in all her vampire glory saunters towards him. She stops in front of Castle and, with one finger, pushes his jaw back up from off the floor. Take THAT Natalie Rhodes. His eyes rake slowly over her entire body, unable to form anything other than stutters and strangled moans.

"Wow…Kate…uh…wh-…mmm."

"Tonight, Rick, it's K-Becks." Castle catches her wink and stares longingly after her as she walks away back into the crowd. Even Ryan and Esposito are a little slack-jawed and they were in on it! Finally, Castle's words return to him.

"BEST. HALLOWEEN. EVER."