Title: "The Sensual Cellular Similarity" (4/5)
Author: Misty /DesertDragon
*Chapter 4: Collision* Rated PG

Chapter 4

'Collision'

Sunday morning dawned cold and sunny, and Penny awoke slightly thereafter, scents of bergamot tea and fresh laundry following her out of sleep. She'd been dreaming about Sheldon.

She raised her head and glanced at the clock: seven-twenty in the a.m.

She growled into her pillow, cuddled deeper into her comforter and tried to fall back to sleep. Two minutes later she realized it was futile and she sat up against her headboard. Her head was a bit watery, but there seemed to be no evidence to suggest a hangover. Just a heavy heart. Her chat with Leonard the night before must have sobered her up some.

She swung her legs over the side of the bed and stuck her bare feet into a pair of fuzzy Hello Kitty slippers. She didn't move much after that; just stared at her Razr on the night stand out of the corner of her eye. She flipped it open.

Sean's and Sheldon's names were right next to each other on her contact list. The text had been an innocent mistake. Leonard had concurred, and said that Sheldon had been pacified as well.

So why did she feel like she had just kicked a puppy? She deleted the text from her phone without looking at it; she had a feeling that it would make her spew in embarrassment. She could only imagine Sheldon's reaction.

She shivered slightly in her jammies and sighed. You can't change your mind about going over there and talking to him, girl, she chided herself. It's gotta be done, even if it's to simply apologize for your error of sluttiness...

Penny chewed on her lower lip. Yes. That's all she really had to do; say she was sorry, make sure they were okay with each other, and be done with it.

This concrete idea propelled her into a warm shower followed by the solid notion that, in the light of day, she could not realistically see pursuing any of her fledgling feelings for Sheldon. She acknowledged them, and that was fine. But as far as she could see, their friendship would continue to be one long, platonic train ride with no deviation from the carefully laid track.

She slipped into a clean pair of flowery sweatpants and her corral-colored hoodie, and quickly dried her hair, leaving it loose. Before they had parted last night, Leonard told her that he would make himself scarce early this morning, and she was sure that they must already be up and about.

Her confidence accompanied her as far as the green door of apartment 4A, faltered slightly as she knocked, and then died away completely when Sheldon answered the door.

It was almost eight-thirty in the morning, yet he was still in his green and blue flannel robe and pajamas. His dark hair was tousled with bed-head, and his clear blue eyes were hooded and weary.

Penny hesitated, those fledgling feelings that had seemed so incidental in the shower began tickling at her nervous system. Damn. He looked wonderful. And human. And (as she swallowed a heartbeat) down-right intimidating standing there, looming over her from his doorway.

"Hey," she said.

"Hello, Penny." Pause.

"Can I come in?"

Another pause and he glanced behind him at his desk. "I was attempting to catch up on some work, but by the look on your face I can tell that will be futile." He moved aside to allow her entrance and picked up an empty teacup and saucer from his work station on his way to the kitchen. She followed him. "Tea?" he asked, impartially.

Penny didn't realize that she was wringing her hands. "Sure."

Why hadn't he said anything yet? She half expected him to begin chiding her for inappropriate behavior as soon as she walked through the door. She watched him striding back and forth in the kitchen, preparing the tea and avoiding eye contact.

Oh, boy. It was like ignoring a giant elephant standing in the room. Or maybe in Sheldon's case, a six-foot tall baby giraffe.

Penny sighed and took a deep breath. "Listen, Sheldon, about the text I sent you, um -"

He stared hard into the tea cups, possibly trying to get them to steep with his brain, and it forced her to stumble over what she wanted to say.

"- I didn't mean to send it to you. I mean-"

"Of course you didn't," he interrupted, his tone unidentifiable.

She paused, staying wary of his usual condescension. "Well... I didn't."

"Fine. And did you just arrive at this realization? Or have you and your new boyfriend been laughing about this over the last several days, enjoying some sort of sophomoric prank?" He turned away from her, forcefully pushing the lid of back on the loose leaf tea can.

If she had been more in control of herself she might have realized that he was simply speaking as a professional prank-ee. But she wasn't in control. She was pissed. She slammed her hands flat down on the island separating them, making him jump a little.

"Goddamn it, Sheldon Lee Cooper! How can you possibly think I am that shallow!?"

He was about to open his mouth and perhaps say something vindictive, she could tell, so she advanced on him swiftly.

Penny looked up at him, her hands fisted over her chest, pleading incredulously with him. "Do you honestly think I would ever do something that mean to you?" She knew deep down that it less about her being offended and more about feeling sincerely hurt.

He must have seen it on her face, or noticed her trembling, because a rare look of shame shadowed his features and his eyes began to bounce back and forth from the floor to the ceiling to the coffee pot and back again, licking his lips nervously. Finally, they settled on a spot on her hoodie.

"No," he admitted softly.

She threw her arms up the air in frustration and moved back toward the living room to keep herself from smacking him. "Then how can you even suggest that? Gah!"

Undeterred, he followed her, trying to regain his air of superiority, raising his voice to prove his point. "Yes. I suppose that's not really in question, is it. No, I think the far more important issue is why you feel the subversive need to be 'over-familiar' with men you barely know."

Ah. Here was the Sheldon she knew and loved. Before she turned and faced him, she stared up at the ceiling and counted to ten, during which the word 'prude' came to mind. She turned, brushed her hair back from her shoulder and crossed her arms. "Over-familiar?"

"Yes."

Penny smiled to herself as she studied him, her anger slowly dissipating. He wanted to fight, ached for it it seemed, if only to resolve any uncomfortable discussion between them. She doubted he was aware of this, but she liked that he was emerging out of that weird shell he had been hiding in for the past few days. It was easier to call each other names than to play nice.

"Hmm." She walked right up to him and narrowed her eyes in mock suspicion. "Maybe there's something else you'd like to call me, huh?"

He kept his jaw clenched, determined he could stare her down from those hooded eyes. Amateur.

"Tramp?" she suggested. His stony expression wavered. "Trollop?" His temple twitched. "Hussy?" She saw his pulse jump in his throat and she knew she'd broken him. "Slut?"

He lost his cool completely, babbling nervously. "God, Penny. No! No. I only meant to imply that... I mean, I meant to suggest that you should exercise..." He proceeded to over-corrected himself a number of times, prattling on in Sheldon-speak until she was able to gather that he was A.) embarrassed, and B.) initiating some strange sort of chivalry. Whatever he was trying to say, she had to calm him down.

Penny reached up quickly and gently cupped his face, from which he was too busy defending her honor to flinch away from. "Shhh, okay, okay. Sheldon, shhh, I got it." Once his lips stopped moving and his blue eyes re-focused on her upturned face, she gave him a long significant look, wanting to make sure that she got this right. "I'm sorry. It was a mistake, okay? And I am so sorry. That text was... sort of... meant for someone else. I just haven't been in my right mind lately. I never meant to make you uncomfortable." He had gotten so quiet during her apology that she cocked her head at him, hoping for an appeal. "Do you believe me? Are we... okay?"

He had moved his eyes away from hers, but nodded his head in agreement. Her hands fell away slowly, her gaze following them down to the crisp, white undershirt under his pajamas and she can see the tension melt from his shoulders in relief.

"Yes," he verbalized finally. "And I accept your offer of apology and recognize that this was a misunderstanding based on misguided use of a passive-aggressive digital medium, all of which was meant for another man."

"Thank you," she replied, twirling a strand of her hair around her finger in uncertainty.

He progressed back toward the kitchen. "Now we can return to a stable equilibrium and …" He slowly came to a stop. She was too distracted with her own thoughts to see him turn toward her, a look of clarity and suspicion crawling over his features. "Wait. Excuse me… 'Sort of'?"

"Huh?"

"The text was 'sort of' meant for someone else?"

She glanced carefully up at him towering over her. Those haphazardly perfect eyebrows of his were scrunched together in confusion.

A thousand natural, cheeky responses ran through Penny's mind, but she was unable to catch a single one. Open your mouth and just say, 'Yes, it was.' Period. Yet, her hesitation spoke volumes, at least to her. Was this the moment of truth? No, no, it isn't. Keep your mouth shut, dummy. Don't stir the pot just to satisfy your impulsive curiosity! That's never a good thing when dealing with Sheldon.

Eventually, she managed a small shrug.

One of those eyebrows arched cryptically. "Penny..."

Damn. He had no idea, he really didn't. Just try it and see what happens, a little voiced whispered. She bounced on the balls of her feet briefly for confidence and raised her hands in truce, hoping to soften the blow. But all that would come out of her mouth was one of Leonard's favorite phrases.

"Here's the thing..."

And then she kissed him.

*

Penny, what are you doing?!

But, of course, it was an impractical impossibility to express his utter alarm at such a thing when Penny's lips were converging and crushing his own. He stood there, slack, while his brain ran a series of uncharted calculations. It took a moment before the large numbers dispersed and his mind happened on that familiar moment of clarity as he deciphered Penny's intentions.

Oh, good lord. A sudden, awkward blush ran through him and Sheldon felt his six foot tall frame ball up with nervous tension and worry, his shoulders scrunching up to ear level, his arms going rim-rod straight. His clenched knuckles dug into the hem of her hoodie and he could not assess if he was pushing her away or keeping her there. Then, amidst considering the variables of implementing his previously aborted rejection, he lost focus.

Her hair smelled clean and sweet like papaya and vanilla. It was exceedingly pleasant. He found himself closing his eyes. Interesting that this felt nothing like his Thursday night dream of her. Her lips were calming, not intrusive. Relaxing, he breathed into her and took a tentative step closer, curious. However, not a millisecond later, he found himself ill-prepared for her reaction.

Penny returned his sigh; this simple action alone was as chaste and discrete as the kiss she was bestowing. Yet, it did all manner of things to him. The amount of endorphins that burst into his bloodstream were overpowering, even painful, and he felt the apartment disappear from around them to be replaced by a blank-white space.

Like the Construct from The Matrix.

The two of them seemed to exist in the weightlessness of theoretical bliss for a short, undetermined amount of time. And then Sheldon began to panic. He waited to see if the analytical part of his brain would load a program instructing him on how to proceed. What was he and Penny's mission in this place? And if such a program sprang into existence, rushing up from beneath their feet, would she disappear, leaving him partnerless?

Could he allow this kind of instability to take precedence in his daily life?

This was like discovering the quantum mechanics of the uncertainty principle all over again, or at least how Einstein had understood it. He could clearly see the equation aloft above their heads, with no resolution.

Sheldon convinced himself indefinitely that, unless Penny, herself, had inherent knowledge of relativistic methodology to rebuke this Uncertainty hypothesis (unlikely), he could envision nothing short of chaos ensuing.

These questions contained both wonderful and terrifying ramifications. All it took was her hand delicately clutching at the lapel of his robe to pull him closer to her and he was able to determine precisely which of those ideals would ultimately win out.

The terror did.

*

Sheldon was quick to disentangle himself from her, and Penny immediately missed his warmth as he took two clumsy steps backward, leaving her discombobulated.

She saw him fight wholeheartedly for impartiality before he could look her in the eye, and even then he began to stammer.

"Penny, I can't be doing this. I just ... can't."

She could see the outright fear in his eyes, as if his world had briefly collapsed like a set of Lincoln Logs and he was attempting to resurrect it with that big brain of his. She stared, confused, at his swollen, slightly wetted lips. Oh, god. Oh, god, had she done that? She had to fix this.

"I know. I'm sorry. I - I ... I really didn't think that through. I-"

He interrupted her, obviously feeling the need to explain himself. "You see, in the Heisenberg Uncertainty principle there are no states that describe a particle with both a definite position and a definite momentum."

"...Huh?"

"They do not have a definite energy, and each time they decay -"

She held up a hand to silence him. She mustered all her bravery, if only to convince him that she felt a mutual wrongness about all of this. Christ. She was probably just trying to convince herself. She had known this wouldn't work. "You don't have to explain, Sheldon. Okay? I just... had a really bad night last night, that's all. I didn't mean for any... of it to leak over on you."

He seemed taken aback for a moment at her insistence; she couldn't tell if that was concern written on his face, relief... or pity. At least he didn't appear to be uncomfortable anymore.

"Let's just forget it, okay?" And she quietly added in her head, so I can go submerse my shame in a vat of ice cream.

Slowly, the suspicion melted away and he pushed himself up to his full six foot, two inch tall height with a sudo-professional air, seeming to find this acceptable. "Agreed."

All the tension whooshed out of Penny as if she had been exercised of some sort of demon.

"Good... So we're okay?"

Those blue eyes of his appeared overcast and a bit somber as he looked at her directly for a moment. Then he nodded politely, their hue warming. "Status quo."

*

It took a while to get back to status quo. Like the aftermath of a car crash, sometimes it took a bit of persuading to get back behind the wheel. Until then, you grasped onto the normalcy of everyday things and embraced complacency.

And once Penny learned to push her feelings aside as nothing more than a crush, it was much easier. This also helped bring on the realization that it wasn't Sean she should have been comparing Sheldon to all along; it was herself. They seemed to share a constant need of validation from each other, something Sheldon would never admit to in a million years, but she doubted that he was conscious of it. That would be her little secret.

Eventually the equilibrium between the two of them settled and she and Sheldon began to ease into their usual, habitual routine.

One Halo night, while they stood in the kitchen together as he poured the leftovers from Soup Plantation into re-sealable containers, he surprised her by bringing up that uncomfortable Sunday morning which was a little more than a month gone by.

"You know, I confess I have now come to understand the motives for your actions on the morning of March the First."

He was being so nonchalant that Penny was afraid to follow his train of thought. She cast a careful glance toward the living room to see Leonard, Howard and Raj absorbed in setting up the Xbox. She crossed her arms defensively and arched an eyebrow at him, waiting.

Sheldon glanced over at her and mistook her trepidation as ignorance. He licked his lips and rolled his eyes, attempting to keep the condescension to a minimum. He took a hold of her arm and gently tugged her over to the refrigerator and pointed at the small year-at-a-glance physics calendar that hung there, one long finger hovering around the last week in February.

"Look," he instructed proudly. She squinted at it in concentration. "Coupled with the unfortunate dating circumstances that you had found yourself in, your peculiar behavior that week easily stems from this point in your menstrual cycle."

"Sheldon-"

"See. I've been keeping track."

Sure enough, in small, meticulous printing - all over the calendar, not just February - were the accurate recordings of all her recent menstrual cycles including many minute details that even she never bothered to pay attention to. Penny's face went slack and her mouth dropped open a little. Huh. Look at that. She should be ovulating.

She gave herself a hard mental shake and tried desperately to ignore the fact that this information was displayed on her neighbor's refrigerator. She bit back any temper that was on the rise, and chewed on her lip. She could see Sheldon watching her out of the corner of her eye, expectantly, like an eager student.

"I did plenty of research to back this up. My hypothesis is valid," he reiterated, sensing her hesitation.

Penny cocked her head at him. His arrogance was actually endearing for once and she realized that she was more than happy to let him come to what ever conclusion he wanted to. Her answering smile seemed to relax him, and she patted his arm appreciatively.

"Aw, sweetie. That's very observant of you."

Before she made her way back into the living room, she caught him looking rather pleased with himself. As per his usual.

Penny sunk down in to the middle cushion of the sofa and waited to be handed a game controller, marveling at the powers of denial.

*

to be concluded shortly....