"You know, Derek, you can…sorta dance!"

"No, no no no no no! See, I just do party moves. You get me onstage on live TV and I'll become like…like a zombie."

"Yes! But, a zombie with rhythm!"

Derek stared at Casey incredulously. "Say what now?"

Casey was bubbling over with excitement, her blue eyes large and brilliant. "You'll be a zombie, and I'll be the beautiful maiden you're trying to attack. That way I get to show off all my dance moves, and you can just act like a creep without really dancing! You'll have an excuse to move slowly and everything! It's perfect!"

"Beautiful maiden?" Derek smirked. But for once Casey was ignoring him, scribbling furiously in her notebook. Occasionally she let out a "hmm" or a "yes, yes" while Derek stood waiting impatiently. No poking, prodding, or "You done yet's?" were able to shift her attention back to him. After several minutes of hemming and hawing, he eventually sat in his chair and flipped on the TV.

Casey immediately snatched the remote out of his hands. Knew it. "Get up!" she barked. "Time to rehearse."

Derek rolled his eyes. "Well, finally. Thought I was off the hook for a minute there."

"The perfect routine cannot be rushed," Casey sniffed. "Not if we want to win." Her eyes narrowed dangerously. She took a deep breath, and Derek wondered, not for the first time that evening, what he'd gotten himself into.

He stood up, and then stumbled as Casey unceremoniously pushed him into a corner of the room.

"Now. I'll come onstage first. I'll do a little twirl." She spun gracefully into the center of the room, and Derek's breath caught in his throat.

"Then," she turned quickly, panting. "I will look for you. And when I signal towards you with my hand," (she demonstrated) "you'll come on."

Derek stood there quizzically, awaiting further instruction.

"I said you'll come on." Casey prompted.

"That's it? I just walk onto the stage?"

"No, silly!" Casey scoffed. "Act like a zombie, ready to devour your next victim."

Derek didn't know if he liked where this was going. Casey's choice of words, along with her seamless way of moving her body, was not something he was apt to expose himself to for very long. It made him start to feel things about his stepsister, things that he couldn't always hide.

But, it wasn't like he didn't want to devour her. He might as well have fun.

Grinning, he extended his arms menacingly and stalked slowly towards Casey. She raised her eyebrows, seemingly amused, then squealed when he suddenly grabbed her hips and moved his teeth close to her neck, as if to bite her.

"Derek!" she shrieked. "You're a zombie, not a vampire." Averting her eyes, she took a big step back and smoothed her hair, as if to compose herself. Derek's smile only grew wider. She was so cute when she was flustered.

"Alright," Casey began again. "Then I'll dance around you more, while you just keep acting like a zombie. A zombie," she emphasized. Derek watched as she started to do a series of complicated moves, only to abruptly push out her chest right against his shoulder.

"Whoa!" Derek inadvertently shouted.

"What?" Casey scrambled back in alarm.

"Do you have to be so…close?" Derek asked, his heart pounding in his chest. Get it together, dude.

Casey sighed. "Derek, it's a couples dance. Like it or not, we have to dance together for this to work. So yes, I will have to be close to you. And," she glanced down at her notebook again, "if you can't even handle me being next to you, then you definitely won't be able to pick me up and spin me."

"Pick you up and spin you!" Derek's jaw dropped. "What happened to me just moving slowly like a creep?" And was that how she thought of him? A creep?

"You agreed to dance with me, Derek."

Derek was about to protest again, but then shut his mouth. Did Casey look…hurt? Why should she be hurt that he didn't want to touch her? She didn't like him, clearly. And she didn't know what she did to him, right?

He sighed. Of course she didn't know.

"Alright. Just show me what I have to do," he grumbled.

Casey tentatively led Derek through some more moves - nothing too difficult, mostly just jumping and following her around like a zombie - and then she brought out the big guns.

"Now, I'll run and leap toward you. And when I spin around, you'll grab my neck and dip me while I kick out my leg."

Derek closed his eyes. This could not be happening.

"Uh…that might be too complicated for me, Case."

"No," she told him patiently. "It's easy. You just have to stand there and be ready to catch me. And make sure I don't fall."

Yeah, and try not to pop a boner on television.

"Okay?" Casey was looking at him uncertainly. "Ready to try?"

"Yeah, yeah."

As promised, Casey ran and leapt toward him, then spun one eighty degrees, ending perpendicular to him.

She was so close. So very very close.

"Now put your hand on my neck and lower me down."

Could she tell that he was trembling?

Still, he obediently wrapped his hand around her neck and lowered her, and then watched with bated breath as she lifted one of her long legs and it brushed against his thigh…

"OW! Der-ek!"

Derek jumped away, startled. He'd dropped her. Oh, no…

"Derek, you have to hold on! Stop messing around and learn the dance, okay? That was just mean!"

He sighed in relief and grinned. She thought he'd dropped her on purpose. Well, that definitely beat the alternative.

"Couldn't resist," he winked, flashing his most charming smile.

Casey huffed and got to her feet. "Well, no more joking. We only have so much time to get this right. Okay, we're almost at the end here. So…" her eyes flitted over her notebook once more. "I'm going to do triplet turns. A few spins," she translated kindly. "And then comes the end when you pick me up and twirl me around. So don't drop me this time. Focus." She glared at him meaningfully.

"Whatever," Derek muttered. How he was supposed to focus on learning the dance moves and calming his reactions to Casey's body at the same time was truly a mystery.

Casey spun around three times - quite impressive, really - and then, surprisingly, stopped, turning to face him.

"Okay, in real dance…you have to try to be graceful."

"Hey, Case, I already told you, I don't do your kind of dancing! That's why I'm a zombie, remember?"

"Yes, but just…" Casey fiddled with her ponytail for a moment. "You have to put your hands where I tell you, okay? Don't just splay them haphazardly all over my body."

Derek's mind went blank. Did she know what she was saying? This night was getting weirder and weirder. How did he get into this situation again?

Casey was blushing furiously now. God, she would be the death of him.

"Just- just let me show you," she stammered, and then quickly - almost too quickly - turned and pressed her back flush against his chest. Before he could think, she took one of his hands and crossed it across the front of her shirt, then took his other hand (stiff as a board) in hers. "Try to spin me."

"I can't do this, Case," he whispered.

"Why?" she demanded, and turned her head to try to look at him, her cheek brushing against his neck as she did so.

Oh, God.

Panicking, he suddenly lifted her and spun her, feeling Casey jump in surprise. Then he placed her back down on the ground as soon as possible, and shuffled away. Awkwardly, he put his hands in his pockets, trying to look nonchalant. No big deal.

To his utter dismay, he saw that Casey was now laughing at him.

"What is wrong with you?" she snickered. "Physical touch really embarrasses you, doesn't it? How have you had so many dates?"

Now it was Derek's turn to laugh. "Don't compare yourself to one of my girlfriends, Spacey."

He felt a glimmer of satisfaction as Casey spluttered indignantly. "That's not what I meant, Derek- why would you even say that- okay, from the top!" she snapped, and, like a drill sergeant, ordered him to his position once again.

The rest of their rehearsals didn't go very well. Not that Derek didn't catch on; after all, he wasn't really a bad dancer. He learned the steps, the timing, his cues.

But he was tense and awkward. He just couldn't feel at ease touching Casey, and he was thinking way too hard whenever she was in close proximity. His palms would sweat, and his heart would beat fearfully like a drum, and he would try to look anywhere else besides her, which often resulted in Casey yelling at him to pay attention.

Casey, for her part, seemed ridiculously judgmental. She snapped at him every few minutes, and criticized even the smallest misstep or placement of the hand (despite the fact that he simply did exactly what she told him) which only made him screw up more. He could tell the pressure was getting to her, and even though he was tempted to mess with her and go back to their regular banter, her nervousness was actually rubbing off on him. After all, they would be on TV. He didn't want to look stupid.

Seriously. How had he come to this?

Finally, the big night came. Casey and Derek had been practicing relentlessly all day at the school. In a way, Derek was grateful, because his dad hadn't bugged him about homework or chores or anything while Casey took over his life with her crazy dance schedule. But her nervous energy had become so unbearable that he honestly didn't know how much longer he could last.

In more ways than one…

"Okay. As far as final rehearsals go, that was…" Casey sighed, defeated. "Really not very good."

Yeah, he couldn't disagree with that, unfortunately. They were about to lose, big time.

"Aw, stepbrother and sister act. Cute."

Derek turned to see Sadia, Casey's rival in the competition and honestly the whole reason he was in this mess, strut into their vicinity with her dance partner. Casey, of course, in her nervous state, was immediately triggered.

"Cute? We are not cute! We are fierce competitors, and you're just trying to psych us out cause you're worried you're gonna lose to us because…Sadia rhymes with Badia! And that's what your routine is - badia!"

Oh, Casey, why…

Sadia didn't break eye contact. "If your routine's as bad your trash talk, we are so winning this contest."

She walked away with her head held high, not giving the pair a second glance.

Oh, it was on.

"Okay, we so have to beat them."

"Totally," Casey agreed. He was standing very close to her, but it didn't feel awkward now. They were a team, united against that bitch Sadia and her stupid partner. Casey was so warm and near and her chest was heaving, and he could tell she was as intoxicated by the competition as he was.

"If only to make up for that Sadia-Badia bit," he couldn't help adding. "Yikes."

Casey hesitated. "Yeah, that was pretty bad."

Derek peered past the curtain as Sadia and what's-his-name took their turn. He couldn't see a single thing wrong with their routine, but Casey understood that dancey-schmancy stuff better than he did.

But Casey was hovering behind him, shielding her eyes with her hands. Great. "I can't look! Are they any good?"

"How would I know?"

When it was their turn, Derek waited behind the curtain on the opposite side of the stage from Casey. She caught his eye, and he tried to smile encouragingly. She nodded, a steely look of determination creeping over her features. That's my Spacey.

The music started, and Derek felt a thrill run through his veins. This was the moment.

Casey ran out onto the stage and began the routine. She was in a powder blue dress that ended just below her hips, and it twirled up even higher when she spun. And her hair was long, and curled, and swung with her as she moved.

In all their rehearsals, she'd been in sweats and a ponytail. And now, she had transformed into an ethereal goddess.

What an absolute babe.

Suddenly, he couldn't wait to get out on that stage.

On cue, she raised her arm towards him, and did something she hadn't during any practice run - she smiled at him; a deep, seductive smile that invited him out to play.

He was quick to oblige. In rhythm, he marched, as a zombie, out to greet her. And he found he no longer minded her needlessly sexual dance moves. When she pushed out her breasts in his direction he couldn't help but think how well her tan skin contrasted with her light, sparkly dress, how he wanted to touch those breasts and kiss them. God, he felt alive.

And Casey was alive! In the heat of the spotlight, in front of the sparse audience and the cameras, she was glowing. She continued smiling and tossing saucy glances his way, inviting him into the dance rather than reluctantly dragging him through it.

When she got down on her knees and flung her hair back with her rear facing him, he could have moaned out loud. And when she turned to face him, he thrust his arms out, right on cue, and the look she gave him from those searing blue eyes was enough for him to melt.

Hell, he knew he was attracted to Casey, but it seemed like she was pretty into him too. Could she know…?

But he couldn't ponder that, because the dip was coming up, that part they'd never gotten quite right during practice. Casey hadn't really trusted him after he'd dropped her, so she never moved fast enough, and he was always too worried about dropping her again to act naturally.

When she came out of the triplet turns this time, he was ready. He shot out his hand to catch her neck and thrust her downwards, and she kept her eyes closed, angling her neck so the light shone on her glistening skin. Oh, God, he wanted to lean down and plant his lips right below her jaw. Would it be weird if he did that? Could he pass it off as part of the dance…?

But he didn't have time to decide, because Casey was lifting her leg, and not like she'd done during practice when it was sort of a swift, karate kick. Now she was moving slowly, sensually, and her leg was bare, and who cared that this was his stepsister, he was the luckiest bastard alive to be holding her right now.

The dance continued, and the final spin came, and Casey confidently placed his hand on her waist this time. Her body was so warm, and thrumming with relaxed, yet exuberant energy. He tightened his grip on her as he spun around, eliciting a small gasp from her, and then the spin was over. He placed her back down on the ground, she did one last little twirl, and then it was over.

When she turned around to look at him, her expression was one of pure joy. She squealed excitedly and shot up, bouncing happily. How did she have the energy for that? He was breathing so hard he thought he might pass out.

Derek walked in a daze behind the stage, absentmindedly holding Casey's hand the whole way. She was still bouncing with every step, brimming with hope.

"Derek, you did it! I did it! We did it! You were brilliant!" And before he could stop her, she threw her arms around his neck and hopped up and down against him. "I knew you had it in you!"

And apparently there's a lot I didn't know about you…

Casey and Derek had performed last, so they didn't have to wait very long to hear the results.

"There's a pair here who knocked my socks off. They were sharp, polished, aggressive, and they did not miss a beat. So congratulations on your victory…"

Sadia stepped forward prematurely, the audacity…

"…Casey McDonald and Derek Venturi!"

They won? Wait, they won!

Casey was gasping and shrieking and jumping up and down in delight. She threw her arms around him again, which made him tense up this time - he was already at one with reality again - but he couldn't wipe the huge grin off his face.

Truly, Derek realized, he didn't care who won. He just hadn't wanted to look like an idiot on TV. But beating Sadia did feel pretty nice. He stole a glance at her. The bitch was fuming. Oh, man, was that satisfying.

And Casey was so happy, so full of light and energy. He was glad they had won for her. Right now he felt like he could lasso down the moon for her if she wanted it.

The rest of the night, from the aftermath of the competition, to the car ride home, to the family enthusiastically congratulating them, Derek was unusually quiet. Brushing his teeth, he furrowed his brow thoughtfully. He couldn't stop one thought from knocking at his brain.

Was Casey into him?

He knew he was a goner, and that wasn't news. But he usually tried to brush off his feelings, mostly because he knew Casey just saw him as her annoying stepbrother. Anything more would repulse her. Or at least, that's what he'd thought. Now he wasn't so sure.

I mean, really, could he chalk all those seductive stares up to stage presence alone? She must want him. And what was with those moves she'd made him do in the first place?

But girls were pretty confusing, Casey most of all. After all, she was like a weird breed of girl…

Would she let him kiss her if he tried?

There was no way.

But the way she'd looked at him…

But she was his stepsister.

Derek spit and looked into the bathroom mirror, and, for once, didn't like what he saw. Casey was right. He was a creep.

Yet, he had to know for sure. Somehow, before the year was out, he would find out what Casey felt about him.