*A/N: Prompt at the end.

Making A Play

a "Den of Thieves" story

Detective Kate Beckett watched the verbal back and forth between Detective Demming and Richard Castle with a not too subtle frown of disgust on her face. Tamera "Tammy" Demming had joined them on the case when it overlapped with a parallel case the other woman was running in Robbery. At first, it had been great. She and Tammy had got along really well, and Beckett thought she'd found a cohort with whom she could tease Castle. But now, as the other two bantered and played off each other, building theory, Beckett felt a strange knotting sensation in her gut.

She had a suspicion of what it could be, but she just wasn't willing to give its voice a name yet.

She wouldn't have had a problem with the two swapping theories if it weren't for the fact that it was eerily similar to what Beckett and Castle shared. In addition, even though she hadn't swung that way since college, there was no denying the fact Tammy Demming was a beautiful woman.

She had long brunette hair that she tied behind her head in a high ponytail, and mischievous blue eyes that almost matched Castle's for their brazen sparkle. Demming was a little more chesty than Beckett—And don't think she hadn't noticed how the other woman had popped one more button than was strictly necessary when she'd caught him surreptitiously checking her out. Beckett couldn't blame Castle for that. He was free to look, but the fact that he did irked her more than it should.

As a result, Beckett had tried doing her hair differently in an attempt to look more feminine, and wore more flattering blouses and jeans. She had spent a good halfway before work squeezing into her current pair jeans because she knew they made her ass look great. She'd been rewarded when she caught Castle staring when she'd bent over to add something to the white board. However, overall, Tammy Demming seemed to be winning the battle for Rick Castle's attention.

Beckett sighed, trying to ignore the pair as she thought about when she'd first met Tammy Demming. It had been in the precinct gym early one morning.

XXX

Kate Beckett was pounding away at a punching bag, trying to work out some of her numerous frustrations with a certain mystery novelist. He just knew how to get under her skin, in both a bad and good way. It left her all confused, not knowing what to think or how to feel. In-between jabs, she caught sight of someone else entering the workout room. The other woman was tall, with long brunette strands that she tied back in a high ponytail before starting on some stretches. Having taken note of the newcomer, Kate continued punching the bag, adding in a high kick here and there. The bag swayed back into her, nearly causing her to lose her balance. Seeing this, the other woman jumped up to her feet and approached Kate with a friendly smile.

"You need someone to steady your bag," the woman said in greeting.

Kate bounced on her feet, and wiped the sweat from her brow. "Are you offering?"

"Yeah. Sure."

"All right. Thanks."

The other woman stepped up and cradled the bag before giving Kate a nod to proceed. Kate threw two punches and then kicked high again, smirking as the bag swayed back, knocking the other woman off balance.

"Oh, you're good," the woman said with a chuckle. "Nice."

Kate grinned wider, having fun, but before she could reply, the shrill sound of her cellphone interrupted her. She gave the other woman a nod of thanks, and then turned to snatch up the offending device off the bench.

Little had Kate known... she had just met the competition.

XXX

Shaking her head, and pulling herself back into the present, Beckett bit her lower lip and tried to concentrate on the case, but with Castle and Demming standing right in front of the white board, it was hard not to witness their flirty exchanges. Her heart clenched and she gritted her teeth as the pair came to the same conclusion at the same time, resulting in them staring unnecessarily long into each other's eyes.

"Wow," Beckett interrupted with a somewhat annoyed look in Demming's direction. "It's like we're all on the same case."

Demming raised her hands in an appeasing manner. "Esposito told me about Ike," she admitted with a cocky smirk. "You have a lead on him yet?"

"No," Beckett shook her head from her spot at the conference table, glancing back down at the files spread out across the surface. "What about Finch's partner?"

"Ah," Demming hesitated, flicking her blue eyes towards Castle for a moment. "There's nothing in his phone or his financials that points to one. But the bank surveillance tapes finally came in. I was gonna scrub through 'em in the morning. If Finch cased the joint in the last couple of weeks—"

"Then maybe the mystery partner went with him," Castle concluded. Once again, Beckett worked hard at stifling the groan, gritting her teeth and breathing through her nostrils as she watched Demming's shift closer towards the novelist.

"Exactly," Demming nodded with a faint grin on her lips. "You want to join me?"

The two locked eyes and Castle matched her smile with one of his own. "Yeah," he bobbed his head, almost comically, way too enthusiastic for volunteering for the tedious task of going through hours of surveillance video. "Yeah, I'd love to."

"Great!" Demming beamed at him. "I'll see you in the morning, then?"

"Okay, great!" Castle agreed. "I'll see you. Until tomorrow."

"Until tomorrow," Demming echoed with a saucy smile.

Castle bobbed his head, and made to leave, pausing halfway, as if on after thought and turned toward Beckett. "Goodnight, Detective."

Beckett swallowed, trying to hide her disappointment at what she'd just witnessed. "Yeah," she replied hastily. "Night, Castle."

Castle offered her a tight smile, and then departed, humming to himself as he walked away. Beckett lowered her head and pinched her lips, knitting her brows together in an attempt to stifle the rising sense of disappointment and loss.

"Hey, Beckett," Demming questioned, stepping over and resting her hip against the side of the conference table. Beckett glanced up, quickly pulling her professional mask down to conceal her conflicting emotions.

"Yeah, Tammy, what's up?"

"Can I ask you something… woman to woman?"

"Um… sure," Beckett shifted uncertainly in her seat.

"You and Castle—is there, uh, something going on there?"

"Me and Castle?" Beckett repeated, shocked by the question.

"Yes."

"No," Beckett was quick to assert, her standard answer to this question.

Demming narrowed her eyes. "Are you sure?"

Beckett licked her lips, feeling her heart pound beneath her breast as she tried to think of a way to answer that question without really answering it. Her feelings towards Castle were conflicted, at best. He irritated the hell out of her, but at the same time there was just something about him that she found utterly… endearing.

"Because I don't want to step on any toes if you—"

"Yes!" Beckett blurted out. Her eyes went wide in surprise. The other detective's expression matched her own, and the two stared at each other for a long moment. Her heart thumped like a jackhammered inside her chest as the silence lingered on into the awkward phase.

Beckett was loath to admit it, but he'd grown on her. She liked having him around. More so than she had ever thought possible. And there was something else. She'd felt it, lying beneath the surface, ever since he pulled her out of her burning apartment building and he'd offered to put her up afterwards while she found her footing. She liked him, as more than just a friend, and despite her reluctance to hold back and protect herself from the hurt he could cause her heart, she was sorely tempted to give in and see what there could be.

"Um… okay," Demming inclined her head, breaking the silence. She brought a hand up to brush back some loose strands of brunette hair. "Yeah. I thought I saw something earlier, but I wasn't sure, so I just wanted to make sure before I made a play, because… damn… it's been a while and he's… he's really something."

"Yeah… he's something, alright," Beckett agreed with a stilted nod, still in shock over her burst of honesty.

"Then why did you not say that be—?"

"It's complicated," Beckett answered, cringing as she said it. She'd used that equivocation far too often.

Demming let out a breath, and offered her a slight nod. She made a move to leave, but stopped at the doorway, glancing back at Beckett with a thoughtful look. "Word of advice, Detective—don't wait too long before you make things uncomplicated. The next woman might not be sporting enough to ask before making a play at him."

And with that, Demming left, leaving Beckett to contemplate their conversation.

XXX

The following morning, after a restless night's sleep, Kate tried hard not to let her disappointment show when she found Castle and Demming already camped out in the video room, both with steaming cups of coffee. It was all too evident that Castle had been the one to supple the delicious hot brew. He was, of course, oblivious to her crestfallen expression, but Tammy had noticed. The detective gave Kate an understanding look, before turning back to Castle and jabbing him in the shoulder.

"Ow," he whined, rubbing his injured arm. "What was that for, Tammy?"

Demming jerked her head down towards their cups of coffee and then looked back up in Kate's direction. A light bulb seemed flash above Castle's head and he leapt up from his seat and rushed out of the room to make her a cup. Once he was gone, Beckett slid down into his spot, narrowing her eyes at the grainy surveillance video.

"I thought you weren't going to make a play," Beckett hissed out in a low voice, keeping her eyes straight ahead, proud of how firm and steady her voice was.

"I haven't," Demming said, not bothering to hide the fact she was offended by what Kate had implied. "I don't take what belongs to someone else. I do work Robbery after all." She let out a light laugh, before turning serious again. "Unless that's changed?"

"No," Kate insisted immediately, shaking her head for emphasis. "It… it's just—"

"Yeah, complicated… I know," Demming gritted out, turning back to the video monitor, annoyed. "Look, Beckett, you gotta be clear here. Either you want to be with him, or you don't. You can't have it both ways. If you're not willing to take a chance with him, you need to step aside for someone else… someone who's actually interested in him. Because I like him, Kate… a lot. He's funny, charming, and God… is he handsome or what? You know how hard it is to find all that in one package!?"

Kate merely looked at her, dumbstruck, unable to find an appropriate response.

"Yeah, that's right… it's damn near impossible," Demming continued. "So you need to make a decision, because if it's still complicated by the time we close this case, I'm making a play."

Not knowing what else to do, Kate gave a nod of her head, trying desperately to ignore the hammering of her heart beneath her breast. That was an ultimatum if ever she heard one.

XXX

They'd just closed the case and watched Esposito's former partner reunite with his family. It had been a touching scene that tugged at Kate's heartstrings. Presently she was working at dismantling the white board, and boxing it all up. Out of the corner of her eye, she spotted Detective Tammy Demming approaching. She bit her lower lip and tried to school her features. Her time was up. She would have to make a decision soon. She didn't know if she was fully ready for a relationship with Castle, if she even wanted one—Oh, who was she kidding!? She did. She really, really liked him. It was more than friendship that was growing between them. And she would really like to explore it and see where it could lead.

"Beckett," Demming greeted with a nod.

"Demming," she replied similarly.

"So… is it always this much fun up here?"

Kate's lips quirked up slightly. "We have our moments."

"That you do," Demming nodded, stepping around from the corner of the white board to stand beside her. "So… what's the word?" she asked, keeping her face neutral.

Kate took a deep breath, filling her lungs to capacity before answering. "Uncomplicated."

Demming's shoulders visibly deflated, and she was unable to hide the disappointment from her face. "All right," she sighed. She shifted her feet and arched her neck around to glance back at the man in question, not so subtly trying to look busy at the Espresso machine in the break room. Rotating back around to Beckett, Demming crossed her arms under her breasts. "Okay, Kate. Prove it. Make your play."

"What?" Kate nearly choked, caught off guard by the unexpected challenge.

Demming smirked at her, as if she'd read her mind. "As I said earlier, I like him… a lot. And I'm not willing to just take your word on it. So… prove it."

"Fine." Glaring at the robbery detective, Kate pulled the last photo down from the white board and dropped it down into the box. "It was a pleasure working with you, Detective Demming," Kate said as professionally as she could.

Ignoring the other detective's matching gaze, Kate stalked over to the break room. She slowed as she approached the door, stopping at the threshold. Heaving in a deep breath to calm her nerves, Kate tried to put on an air of casual interest as she leaned against the doorjamb.

"Hey… Castle? What are you still doing here?" she questioned, proud of her ability to mask the butterflies in her stomach. This was huge. A lot was at stake. This had to be done right.

"Hey," he smiled, glancing up from the cup of coffee he was pretending to make. "Just about to leave myself. Good job closing the case."

"Yeah," she said in agreement, nodding her head. She flicked her eyes up and looked directly in his. "We make a good team, Rick."

The use of his first name startled him, instantly alerting him to the shift in the conversation. He gazed at her with a puzzled expression.

"Um… yeah… we do," he replied slowly, looking completely and utterly baffled.

Taking another breath to fortify her courage, Kate glanced back out at the bullpen, spotting Demming waiting patiently by her desk. The woman stared back at her with a cocky grin, obviously suspecting Kate of chickening out. Huffing, Kate spun around, decision made. The potential of what she could have exceeded the risks. It was time to stop stalling. It was time she listened to her heart instead of her head.

Without any warning Kate grabbed Castle by the face and closed the space between them, pressing her body flush against his as she pushed up on her toes and rammed her mouth against his. Startled at first, Castle's hands flailed around for a second, before finding purchase on her hips. His fingers curled tightly into her as he pulled her closer, responding in kind, deepening the kiss. Kate moaned, wrapping her arms around his neck as she melted into him.

The need for oxygen soon overpowered the need for each other, and they parted on a heavy gasp.

"Kate," panted Castle, chest heaving as he glanced down at her questioningly. "What are you doing?"

She quirked up an eyebrow saucily and grinned at him, nipping at his lips, and stroking a hand down the side of his face. "Making a play."

prompted by gostopow from castlefanficprompts on tumblr: AU Season 2 what if Demming was a female and interested in Castle. What would Kate's response be when asked if there was anything between Castle and her?