Disclaimer: All recognizable content and characters are the respective property of ABC and the creators of Castle. The world of Castle is a mighty fun sandbox, and I'm only playing in it.

AN: This is my first ever story, so please leave a review and let me know what you think!

Chapter 1 - Down the Rabbit Hole

Peeking around the stair wall and into the bullpen, her eyes scanned over the room filled with her colleagues with a hasty precision only a detective could acquire. Things were as normal as a typical day at the 12th precinct could be: Ryan was craning over Esposito's shoulder, both ogling at something on the screen; Montgomery was pacing in his office, idly tossing an old dirt-stained baseball in the air while talking on the phone, and many others in uniforms were casually walking by, some with folders in their hands, others guiding perps to lock-up…

Perfect.

As quickly as the glimpse of her smoky brown eyes cased the room, she snapped back behind the wall. She had to be alert; she had to be careful to look normal- well, not suspicious at all- if that were even possible at this point. Steeling herself, she took one last glance up the stairs she had just descended and draped the damp towel in her hands around her neck.

If it weren't for the situation at hand, she would have mentally congratulated herself with how deftly she maneuvered into the room, blending in with the usual bustle of people coming and going as though absolutely nothing suspicious was going on at all- nope, absolutely nothing at all…

Her legs were sore, aching for rest, yet it seemed fate decided to put the slowest moving group of cops in her way. Stealing a peak around a burly officer, she saw her salvation, and that rickety old chair of hers had never looked so soft and inviting before.

Biting her lip, she focused all her thoughts on that chair as the throng of officers slowly shuffled along, trying with every ounce of her willpower to forget about how badly her knees were beginning to tremble, how heavy her eyes felt, and the glowing smile that threatened to hint at exactly how she got that way.

Fate seemed to give her a tiny morsel of mercy when the officers in front of her suddenly banked left, towards the coffee machine in the break room. Her shield from all of those suspicious eyes that she just knew were boring holes into her was gone; but this was her chance. Gathering her last vestiges of energy she darted towards her desk, careful not to bump into the chair beside it. Her hand brushed the cold metal surface of her desk and she breathed a sigh of relief. She made it! Closing her eyes, she inhaled the crisp scent of victory; thanking her lucky stars that no one had caught onto her-

"Yo, Beckett!" Esposito's voice shot into her ears like a cannon blast, causing her short-lived mental victory dance to die a very quick, very pitiful death, not to mention making her jump a little.

"Where have you been?" She heard him say. Frozen on the spot, and still completely unsure of what her face would actually belie, she kept her eyes trained on the bouncing elephant screensaver on her computer as she replied.

"Training."

Oops. Her voice wasn't supposed to still sound that… husky.

"You've been working out in the gym this entire time?" Esposito asked incredulously.

She kept her lips tightly shut. She most definitely did not want to reply to that.

"You alright, Beckett?' Ryan piped in, the screechy sound of his chair filled her ears; no doubt he was facing her too. "You were up there for… two hours." The detective paused, undoubtedly for effect. God those two are such hams.

"Correct me if I'm wrong Detective Esposito," Ryan assumed a serious voice, "but doesn't Detective Beckett usually stride out of there exactly one hour after she starts her workout?"

"I believe you're right, Detective Ryan."

"Hmm." Ryan replied.

"Hmm." Esposito agreed.

Her senses went on high alert. Had they already smelled blood in the water? Could they tell something was up?

"I'm fine, really."

"Oh? Are you sure?" Ryan pressed.

"Yeah, you sound a little, I don't know… winded." Esposito added to his partner's observation with an unnerving level of humor seeping into his voice.

Mindful that her legs were screaming for rest, she steeled herself one more time. She was tired and wanted nothing more than a very soft bed and melt into a very happy, contented pile of goo- but she could do this. All she had to do was give them a quick, commanding, and most definitely a non-husky reply, and they would be out of her hair. Just say the right thing and they will leave you alone. Act normal. Say the right thing

"It got a little rough."

And with those words, the inquisition of Kate Beckett began.

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2 Months Earlier

"Castle!" Detective Beckett hissed the very moment the elevator doors opened and she saw the commotion. Around her desk, a group of officers were huddled together, each facing towards something, somewhere in the center, laughing and cheering wildly. It didn't take a rocket scientist to guess what, or who, that something was. Only to make matters worse, Kate was not alone.

Beside her, a tall grey haired man who had yet to take off his issued pitch black sunglasses, looked ahead with the same stony demeanor that hadn't left his face since she he introduced himself in the building's lobby.

"5…4…3…2…1!"

The room broke into cheers and applause.

"Is this establishment always this lively, Detective?" The man asked with not a peep of amusement as they stepped out of the elevator.

"No sir, Agent Brooks." She quickly replied, forcing herself to smile as she gestured for him to follow. Prying her way into the group of people, all of the color drained from her face when she saw just what Castle was doing.

In front of Ryan and Esposito, where Castle's face normally should have been, instead she saw the two detectives holding a pair of legs. Following them down, she saw Castle's face, brimming from ear to ear with a lopsided smile, although his face was turning a few impressive shades of purple. Fire had surely surged in her eyes, for the moment she looked back up at Ryan and Esposito, they caught site of her and immediately dropped the millionaire author and broke for safety of the break room.

"And that, ladies and gentlemen, is how you break an alibi!" Castle stood slowly, all the while slightly bowing to the throng of clapping, starry-eyed officers gushing over him.

"Castle, what in the hell are you doing?" Beckett hissed at him, completely forgetting the presence of the federal agent behind her. Her tone was enough to frighten away the rest of the crowd.

"Oh!" Castle whipped around, and if were even humanly possible, his smile grew even wider when he turned to her, not to mention those blasted blue eyes of his started dancing with far too much merriment for her liking. "Good morning, Detective Beckett. I was just showing the guys how it was impossible that Carmel Sucha saw Michael Franks die from too much blood rushing to his head by-"

His excited rambling stopped short when he slowly started to sway a little. Before Kate could decide on whether to catch him or to just kill him, the dizzy author fell back down onto the linoleum floor with a loud pop. From the way he was looking blankly around, vainly attempting to lift his head, she momentarily wondered how well Castle would have done if he had followed his mother into comedic acting. Her anger vanished instantly, replaced with a feeling of… well, she wasn't quite sure. When she was sure that neither Castle nor Agent Brooks was looking at her, she allowed her lips twitch into a tiny smile. The man certainly knew how to entertain.

"Is this Richard Castle, Detective?" Agent Brooks stepped up beside her, all the while looking down impassively at the groaning man on the floor.

Reminded of the agent's presence, she went back into detective mode. "Yes."

Castle slowly lifted himself up, noticing the burly agent for the first time. Extending his hand, he gave the agent a warm smile. "Hi, I'm Richard Castle-"

"New York Times bestselling author, currently working as a consultant for the NYPD Homicide Division. Father unlisted, mother Martha Rogers. Father of Alexis Castle, married twice, divorced… twice." The agent made no motion to shake his hand.

"Um, yeah…" Castle slowly retracted his hand, while giving Kate look of confusion. "That's me in a nutshell."

"A pleasure." The agent drawled. "I will need you two to accompany me to your captain's office. There is something rather urgent we must discuss."

Brooks immediately began walking crisply towards Montgomery's office. Dusting himself off, Castle quickly shot Kate a questioning look, to which she merely shrugged in reply. The pair walked into the office right behind the agent, each of them wondering just what in the world was going on.

After a quick exchange of formalities between Montgomery and Agent Brooks were done, the captain decided to break the ice.

"So what brings a Fed to my precinct today?" The Captain motioned for him to sit.

"CIA." He said as he remained where he stood.

"Beg your pardon, Agent Brooks?" Montgomery asked.

"I am a special investigator for the CIA. And to answer your question, it pertains to a double murder that happened in your area at 6:02 this morning."

That got Castle's and Kate's attention.

"Sir, I've received no calls of any murders today." Beckett interjected.

"That's because," The agent peered at something behind Castle and Beckett. He marched in between them and unceremoniously slammed the office door. "A murder of this… sensitivity, is dealt with by us first, Detective."

"Then why are you here?" Montgomery asked coolly, he wasn't too keen on anybody doing anything with a homicide in his territory.

"I will get straight to the point." Brooks said. "First and foremost, the two people that were murdered were a geneticist by the name of Paul Krashinko, and Senator Alvin Burbury."

Castle visibly tensed beside her. He whispered to her, "The U.S Senator?"

"Second… Senator Burbury left a voicemail to the Mayor's office." Pulling out his cell phone, Agent Brooks held it up and pressed a single button.

There was a loud scratching sound in the background, mixed with the frantic yells of someone nearby. Through the chaotic shouts and running feet, a chilling scream pierced through the tiny phone speaker and a loud pop rang out. For a moment, there was total silence, but then heavy breaths began to grow closer and closer.

"Can't let them win… find Tanner," came the voice of the Senator.

There came a sudden blast of sound and screams, causing Kate and her partner to flinch out of mere instinct. The dull thuds of doors slamming came, then the pounding of footsteps over hardwood floor.

"If you receive this, mayor, find Detective Kate Beckett and Richard Castle."

Kate and Castle leaned closer to the cell phone, both of them holding their breaths.

"They broke this case, and they will be the ones that will end it." Strong footsteps were growing closer to the senator, and judging by how ragged his breath was becoming, it was his killer.

"Find them!" The senator shouted frantically. A gun cocked, slowly and deliberately. It sounded so close...

She felt the fingers of Castle's warm hand twine into hers, and she briefly wondered if it was to calm her nerves or his.

"Tell them Rathborne… Rathborne isn't dead."

The senator gave an unearthly scream before being forever silenced by a final deafening boom.

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AN: I welcome any and all comments or questions. So again, please review!