The Paternal Catalyst
Rating: PG
Word Count: Over 44,000 in all
Disclaimer: I own nothing you recognize except California. That I rule.
Spoilers: Up to the Maternal Congruence
Summary: Because of Penny's father, Penny finds herself hiding in the laundry room while Sheldon constructs a dating formula and Leonard performs human experiments.

Author's Note: In this fic, Bernadette and Howard are broken up. I originally had a subplot that revolved around their break-up and make-up. However, I couldn't really work it in without disrupting the flow. I MAY write it as a companion piece but as of now, consider this fic AU in that respect.

(This fic was beta'd by the charming talkingmetaphor without whom I would still have the shoddy grammar that comes from writing while an insomniac)

Thanks everyone for your comments/criticism!

21

Leonard

They'd gone to the movies together before, just those two. Leonard new this, was aware of this. After all, when its movie night, Sheldon would demand whoever was available to participate. There were times Penny was the only one available. Usually Leonard, Raj, and Howard would lie and bow out so they didn't have to deal with his picky movie preferences. Generally they had the same taste in movies but not in theaters. Sheldon was incredibly picky.

Leonard had a not-so-secret (among his friends) love of mindless action movies. Sheldon hated them for reasons he would be thrilled to disclose upon anybody, willing or otherwise. Leonard didn't mind that his roommate refused to see those movies; he understood they weren't for everybody. It wasn't the movie-seeing that bugged him, but the fact that he gave and gave for Sheldon who rarely returned the favor, and even then with great complaint.

Now Sheldon was with Penny. Penny who didn't live with him but Sheldon let con him into seeing some chick flick. But the biggest problem on Leonard's mind was what they were talking about. Eventually Leonard wanted to be friends with her again; he missed her in that sense. Sure, he'd made a few mistakes and said some things wrong. He wanted to rectify it. He was just afraid Sheldon was disclosing all his flaws to Penny, or blabbing other things Leonard had said about her. He'd done it before.

He put his foot down and forced himself to man up and talk to Penny when she got home.

He sat on the couch and didn't turn the TV on, so that he could listen for their return. He determined he'd have exactly eighteen seconds from the time Penny's foot hit the fourth floor landing to the time she disappeared into her apartment, where she'd avoid him. He didn't have a script prepared like last time, which was dangerous. Then again, the script last time didn't do much good either.

Leonard was working on his dissertation when Penny's high-pitched giggle sounded. In a semi-panicked state, Leonard bolted to the door and threw it open.

Penny and Sheldon were ascending the stairs side-by-side. Leonard was relieved at first, to see her smiling--no, beaming. It was the expression she wore whenever she was bating Sheldon, who was glaring at her. It was two things Leonard noticed that threw him. One, Sheldon's glare was only at half-mast. Was it a non-verbal bazinga? It was rare Sheldon wouldn't glare without feeling behind it. In fact, if asked to sit and really think about it, Leonard was pretty certain Sheldon never wore that expression meaninglessly. The second--and this was possibly the most surprising--was Penny. Leonard was expecting the bitter, angry Penny he'd left, or the sad one he sensed was inside. She was so much the antithesis of either, maybe even more so than he'd ever seen. She positively glowed, her eyes merry and smile genuine.

He hated to ruin her good mood. 'Penny,' he said and worried his voice wobbled a bit.

Both gazes snapped onto him--Penny getting a flush to her cheeks and Sheldon looked annoyed. When they reached the landing, he said, 'Can we talk? Please?'

To his disbelief, she didn't put up much of a fight. Or one at all. In fact, she seemed as though she'd already predetermined the events. 'My thoughts exactly. My apartment?'

Sheldon wore a mask of horror. In a low voice, one he no doubt assumed Leonard couldn't hear despite their proximity, said, 'My words thus far have gone unheeded. That said I feel it necessary to warn you against doing anything brash, Penny. I know the pheromones produced and nurtured by your continuous coitus with Leonard might get the better of you but you must fight it. If it would help, I can plug in the updated information you submitted into my formula.'

Formula? Leonard wondered. Since when did Penny and Sheldon talk math?

Instead of getting flustered, Penny merely smiled kindly at Sheldon and promised, 'don't worry, Sweetie. We're not getting back together.' Then she started toward her apartment.

Leonard followed, or tried to. Sheldon positioned himself as a barrier and opened his mouth to speak. Leonard merely sidestepped him and followed Penny in.

Her apartment had the beginning stages of disarray and so only had to move one shirt off the sofa to make room for both of them. His palms were moist as he sat down so he tried to rub them on his jeans. 'Listen, Penny… I want to apologize. I didn't mean what I said. Well, I meant the part of us breaking up. But . . .' He looked down at his hands, worrying he'd make it worse. 'You're not boring. I made it sound like you were and I'm sorry. You're very interesting and fun to hang out with . . . I just . . . I didn't feel a connection when we talked. When we were friends there was that connection and it was fun. We just . . . we don't talk when . . .' Oh, this wasn't going anywhere good. Still he tried; what was the alternative, after all? 'We weren't ourselves with each other. I tried to act less . . . geeky and you . . .'

She protested, 'No, I was myself!'

'Penny,' he told her, and to his own ears he sounded like Sheldon revving up to give one of his I'm-right-and-this-is-how-you-are-stupid speeches. Maybe he had lived with him too long. 'You lied about graduating community college.'

'But--'

'Remember when you wanted to understand what projects I was working on?' The memory was manifesting as he spoke. 'You didn't just ask me, the one working on it, what was going on. You went to Sheldon.'

'Well, Leonard,' she practically snapped. 'You're so much smarter than I am that I didn't want to look like a moron. I wanted to impress you.'

He almost pointed out that Sheldon was much smarter than he was. But he knew she'd only respond that she hadn't been dating Sheldon. It was veering way off track and he wanted to get it back on. 'That's the thing, Penny. Instead of being yourself and letting me learn who you were, you wanted to show me something you thought I wanted.'

With her face that menacing and finger wagging in his face, he couldn't help but remember her little tale about Junior Rodeo. 'Now you listen,' snarled Penny. 'Don't you make it sound like I came here to beg you to take me back. I didn't. In fact, I came here with the intention of telling you I'm over you.'

'Over me?' he repeated.

She looked ready to strangle him but at that second, Leonard heard a soft mewl. A small calico kitten manifested from beneath the coffee table and leapt onto Penny's lap. Its tail up in a question mark, it looked up into her face and let out another small cry. The effect was immediate. Her expression changed so dramatically and so quickly, he was certain had he filmed the event with a high-speed camera, the transition would only last a couple frames. She hooked one arm around the cat to herd it into her chest. It nuzzled there, and Leonard could hear it purring. When she met his gaze again, it wasn't so pissed. It was as if the cat had some sort of tranquilizing effect. 'Leonard, I actually wanted to talk to you after the movie. I came here to tell you that you're right. We aren't good together; we aren't ourselves, and we nearly have to get drunk to have sex. As friends, we're fantastic but as boyfriend-girlfriend? We suck. I want to be friends again, Leonard.'

He felt relief and half-mindedly wondered if the cat had something to do with it. 'Oh good--'

She wasn't finished. 'But, you kind of pissed me off, Leonard. First you tell me you used me for sex and then you say I'm crap at conversations. When I come to talk to you, you start accusing me of who-knows-what for no reason.'

'But I didn't use you for sex!' he cried, gripping handfuls of his hair. 'You're beautiful and perfect. You paid attention to me. I thought I was in love with you, I swear I did! And I didn't mean I didn't think you were--'

'Stop,' she says, only she doesn't seem so mad just tired. 'I understand those. I just . . . I need some time. I do want to hang out with you but I think for now, it should be with someone else there, too. Like the guys.'

'Really?' he asked, hopeful.

She smiled. It wasn't her full mega-watt smile she usually bore, but at least it reached her eyes. That was a start. 'I think we're going to be fine. As friends.'

For a good long time, he didn't have anything to add. And she didn't seem like she needed to say anything. It felt settled so he thought it was a good time to change the subject. 'So . . .'

'We should try to do something. The whole group,' she suggested. 'Maybe watch the Star Trek movie at your place? The first one?'

He nodded and they fell silent again. 'Penny, your cat,' he tried lamely, gesturing to the feline which had now curled up into a tiny ball, not much larger than his fist.

She looked down in surprise, as if having forgotten its presence. 'Schrödinger?'

He blinked. 'Schrödinger?'

'Yeah.' She let out a small smile. 'Named after Erwin Schrödinger. He did the cat experiment, you remember?'

'Yeah, yeah, I remember. Penny, don't take offense but . . . did you buy him because you were lonely?'

He flinched, expecting assault but she didn't move to shove him out the door, and there was no rage on her pretty features. This expression was something he couldn't read, but guessed to be somewhere in the neighborhood of confused. 'You don't know?'

'Know what?' he hedged, fearing a trap. He imagined Sheldon's horrible impersonation of Admiral Akbar, warning, It's a trap!

As if sensing it was being spoken about, the cat--Schrödinger--stood up and stretched, letting out a yelp of a yawn. He appraised Leonard sleepily before plopping down where he was. 'Sheldon got him for me.'

If there was an explanation, she wasn't forthcoming with it. She just watched him, waiting. 'He . . . gave you the money for it?' he tried.

'No,' she said emphatically. 'He actually got Schrödinger for me, surprised me. It was a gift.' She looked a bit misty-eyed at this declaration.

Hell, he would have been too, had it happened. In all the time he'd known Sheldon, the theoretical physicist hadn't bestowed a gift on anybody. Unless you counted those Tums Sheldon got him to ease his gas. Leonard didn't.

Penny was still talking. 'Yeah, the way he explained it, I think, he noticed I was sad so got me a cat to cheer me up. And because he's Sheldon, he got me a hypoallergenic one.' Then she rolled her eyes as if this was just another part of Sheldon's weirdness.

That sobered him up real quick. Leonard remembered when he was looking at those cats. Penny was obviously obliviously happy; whatever Sheldon told her, she seemed to have accepted. 'Nice. Well, look. I actually have a presentation to prepare for the undergrads. So I'm going to go back to work.' He stood. 'And you know, I'm glad we can be friends again. Later, Penny.'

He couldn't get out of there fast enough.

'Sheldon,' he barked as soon as he stepped foot into the apartment they shared. He spotted Sheldon sitting at his desk, fingers tapping on the laptop's keyboard. 'Leonard, the acoustics in the apartment are perfectly satisfactory,' said Sheldon without looking up from his screen.

'You bought her a cat?' pressed Leonard, standing over him. Though the height difference between Sheldon's six-two and Leonard's five-foot-five evened out the playing field a bit. 'You bought Penny one of those hypoallergenic cats?'

Now their eyes met. 'Is your vision so terrible you need someone to confirm what you think you saw?'

'Sheldon, the cheapest of those cats was two-thousand-dollars!'

He didn't seem to be distressed by this declaration. 'I'm aware,' he told Leonard. 'I didn't pick the cat by its price, but I've read that certain temperaments match with certain owner's temperaments. If the kitten price at the minimum had met this qualification, I would certainly have purchased it. As it was, I had to go up in price.' There was a second of silence before he added, 'If you were wiser with your income, you might have similar funds.'

Sure, Sheldon wasn't exactly stingy with his money. If you needed it, he could be counted on to lend you whatever you needed. Well, you might get a lecture or two (at least for Leonard. He never seemed to criticize Penny) but a small price to pay. So while Leonard had never witnessed Sheldon lending more than a couple hundred dollars, he felt it safe to assume upwards of a thousand dollars was a bit extreme. Even then . . . 'Is she going to pay you back?'

Leonard waited for an affirmative. Sheldon was selfish. He loaned money freely but loaned was the operative word. But Sheldon answered what he suspected. 'There were no pre-agreed upon terms of an exchange of goods. The cat was not requested but offered and neither of us mentioned repayment. Had Penny offered, I would have turned her down because I don't want a cat.'

It took Leonard to understand. He did have an IQ in the 170s, after all, something people forgot about next to Sheldon. 'No, I mean compensation for the value of the cat you purchased for her.'

The Texan stopped and blankly at a wall. Then he turned and said, 'Unnecessary. The act is seen as a donation on my part, a gift for the layman and if I am to understand correctly, gifts are not reimbursed.'

'Sheldon, since when do you freely give gifts to people?' Leonard was exacerbated. He wasn't sure if his roommate was deliberately answering in curt, simple responses just to make him struggle or if Sheldon truly was answering entirely. And that made him even wearier.

Sheldon met his gaze evenly. 'By your actions and if I am to understand correctly, your oration explaining the reason for your desire to shift the paradigm between you and Penny, was severely flawed and misleading. It caused Penny to spiral downward back into addictive behaviors, the favored one being online gaming. If you'll recall two years ago when she first began this trend, I was the one who suffered. The cat, I saw, was a viable distraction for her. In short, Leonard, I need my sleep.' Then he turned back to his computer, pointedly typing away and ending the subject.

Except Leonard could have sworn Sheldon's eyelid twitched, just slightly. Facial tics were Sheldon's tell, to use gambling vernacular. However, whenever he was lying, Sheldon's face would dance as if a thousand tiny motors were controlling separate parts. It was probably nothing, due to fatigue or stress, yet it still tugged at Leonard, made him uneasy. If he were to analyze the past couple of weeks, he would find nothing really sat well with him. Well, Penny forgiving him was a relief, yet it felt tainted. Not as if she was dishonest or had ulterior motives. He couldn't really identify it but knew it was similar to the current situation and also, he was surprised to discover, not unlike the entire trigger, when he'd found her in his apartment wearing Sheldon's shirt.

Theoretical physics was Sheldon's terrain but Leonard knew enough about it to know that if one found repeated occurrences in different situations, it was something to be investigated, to uncover the connection and identify the causation. The three aforementioned events had produced the same slightly hollow feeling in his gut and contained at least one of the same two people. It wasn't a leap to suggest the reason he felt this way was the same all around. The whodunit was, however, the tricky part. See, Leonard had no idea.

Leonard wasn't usually the type of scientist to stare at a formula until the answer magically manifested itself in his mind. He had to write it out, as if the movements of his fingers tightened up the strings in his mind and everything seemed to clear itself up with each keystroke. When he'd had his crush on Penny and was analyzing every word out of her mouth, every reaction, he'd talked it out with his friends. But he knew Sheldon would be no help, especially as he was one of the subjects to be studied, and the thought of bringing in Raj or Howard made him feel crowded. He hadn't gotten the answers with that method anyway and perhaps thinking of it scientifically would help.

So he sat down and started writing down the different events. There were others, but these were the main ones, they felt like it at any rate. As he wrote, however, he did stumble across another time he'd felt similar and that was when he'd had dinner with Penny, her dad, Raj, Howard, and Sheldon. It was momentous in that it was the first time he'd actually realized he'd felt different. It was the same night he'd first accepted that maybe he and Penny maybe weren't meant to be. Somehow, though this was the second incident, it felt like it held the most answers.

Starting with the most recent, as it was freshest in his mind, he wrote down everything he could remember about the different circumstances. His springboard was to cross-reference them to find constants. It was, after all, what he'd do with a math problem. Because he knew, (from a good amount of Sherlock Holmes he'd read as a child, the only leisure reading his mother allowed) it would be foolish to overlook the minutest of details, he wrote down everything from the weather, to the decor, to his general mood proceeding. It was, predictably yet still with surprise, upon the dinner that he felt his first strike. He'd expected greater difficulty and yet, there it was.

The details he'd gathered all did seem random and unimportant. Indeed even time of day wasn't anywhere near similar. He was beginning to feel quite silly writing down shallow information when he did find something significant. It was during that supper that he got the feeling he wasn't actually in love with Penny. Going back just slightly further, what had triggered this thought was that he didn't have a bond with her.

Not like Sheldon did.

And the first time, when he'd gotten the cold fear she'd cheated on him with his best friend, he'd felt it there, too. He'd later figured the reason it bothered him even further than anybody else was that closeness between the two. He had to admit that of his friends, Sheldon was the obvious choice for Penny and not only by Sherlock's elementary. Penny cared for Sheldon. Sure, she loved all of them but it seemed to be Sheldon she felt comfortable being herself with. She'd told him about her lack of a college degree, asked him to teach her physics. It was a strange thought because, in Leonard's opinion, Sheldon was the worst person to trust entirely. The way Penny did, at least. Sheldon was selfish and at times, really couldn't care less about anyone but himself. He didn't understand tact and would easily lie out a person's weak spots for them, usually demeaning them. He'd never let Penny forget how much smarter he was than her, yet she didn't have a problem sharing her flaws with him.

So his friend and ex had a connection. Why would that bother him? The acid of jealousy in his stomach was much weakened by now; admitting he didn't have feelings for her took care of that better than Tums ever did.

As he wrote, Leonard remembered first meeting Penny and the way she looked at Sheldon, the way she flirted. It wasn't the first time Sheldon managed to woo some girl. There were a few times when a young undergrad would swoon at Sheldon's brilliance. Unless they were the stalker type, the crush died fairly quickly. Or he spoke bluntly about something and inadvertently flattered the woman, as with Raj's date. Though this didn't seem to be either reasoning for her infatuation, Penny still flirted. It didn't bother Leonard too much because he knew she'd eventually see his true colors. And sure enough Sheldon had to break into Penny's apartment and clean, which killed her feelings pretty effectively.

Or had it?

Even without his delusional goggles, Leonard knew there was a time she actually did like Leonard, if not off and on. Yet when she came over, whom did she talk to, even going out of her way to do so. She seemed to yearn to push Sheldon's buttons the way none of the others would. He'd thought this was because she refused to accept Sheldon's insanity and this of her Leonard admired. Maybe she was also doing it for her amusement; that, he was sure, was one of the reasons. He now wondered, however, if another wasn't because Sheldon gave her attention. Because--and the memories were hitting him almost too fast for his fingers to hit the keys--whenever he did talk directly to her, she was focused intently even when it was some long droll speech she surely had no interest in. And Sheldon's compliments to anyone were few and far between, sure. But usually the reactions to the rarities were shock, followed by more shock. Penny was surprised, sure, but then would smile so brightly one would think she'd received the breakout role she'd been dreaming of. She glowed.

And Leonard paused over his keyboard and wondered into the Land of the Impossible. Maybe, just maybe, that joy wasn't because of the rarity, thus value, of the compliment. He looked over at Sheldon, who was oblivious to his roommate's musings and merrily typed away on the Dell, a glazed yet pleased expression on his face. Did Penny still have that crush on Sheldon? And surely if it had lasted this long, it had to have deepened, truly stood the test of time.

Occam's Razor stated that the simplest solution, no matter how ridiculous was usually the most likely. Leonard had to admit that Sheldon did have a charm about him. If he were truly a horrible human being, Leonard wouldn't have stayed his friend. Sheldon was never intentionally malicious and he did try to help in his own ways (sharing facts, informing people on aid to their bowel movements, if sadly, in front of attractive women). Sure, he insulted people but it was usually unintentional. It wasn't that Sheldon didn't care about others' feelings; he just didn't notice them. And he'd been nice to Penny, even before the cat thing. Leonard figured he just couldn't see Sheldon as a mate because, well, he lived with him. Also he wasn't gay. But mostly because Sheldon didn't really seem like he'd work as anybody's boyfriend. Hell, Leonard wanted to kill the man at least three times a day and that was just living with him. Being tied to him?

But Leonard had a solid hypothesis and if this were the scientific method, his next step would be to perform experiments. Leonard felt silly but his other methods of figuring things like this out (asking his friends for opinions, then worrying it to the nub) hadn't panned out very well.