Disclaimer: All I own when it comes to Big Bang Theory are the DVDs and three t-shirts.

A/N: Written for this year's Big Bang Big Bang challenge! Much thanks for Nicole for being my beta and giving support as needed.

Chapter 1

The beeping of his alarm jerked Leonard out of his sleep. Even before opening his eyes, Leonard felt that something was different. For some reason, he had an overwhelming urge to just stay in bed and bury himself beneath his covers.

Priya. That's right. She was flying back to India today. After months of dating, and hiding him from her parents, she'd also hidden from him that she'd be returning home.

She had wanted to try a long-distance relationship, but Leonard knew he was hardly able to maintain a regular relationship; surely one with thousands of miles between them would be even more difficult. And he was still nursing a bruised ego from her insistence that her parents not find out about them. So he'd broken things off, and while it was hard (she had been his longest relationship, after all), at the same time it was easier than he'd expected.

For a minute he considered calling in sick, just taking a day off to do absolutely nothing. But as tempting as that sounded, he was finally getting to use the new cryogenic centrifugal pump, and he really couldn't afford to miss a day while it was available.

He finally cracked his eyes open against the early morning sunlight, and for some reason was surprised to see his blue comforter across his bed. But he'd been using that blanket ever since he moved in, almost eight years ago. Of course it would be there.

Shrugging it off, Leonard got out of bed and continued with his normal morning routine. Bathroom, teeth, breakfast, clothes... Sheldon was ready as usual right on time, and they drove to work without incident.

Leonard still couldn't shake the feeling that something was different, but he couldn't place his finger on what exactly it was. It was akin to having a word on the tip of your tongue, just out of reach. He pushed the thoughts aside when they arrived to the university, intent on getting the most out of his time with the new equipment.

The morning passed quickly, and slightly after noon Leonard made his way to the cafeteria for lunch. His last test had ran longer than he'd expected, and by the time he had his tray of food, Sheldon, Howard, and Raj were already seated and eating.

Leonard began to walk towards them, but after only a couple steps stopped cold, once again overwhelmed with that strange feeling he'd woken with, that something was not right. Only this time, he could tell it was somehow aimed towards Raj.

It was so unexpected that it took Leonard a few moments to place what exactly it was he was feeling, and was surprised when he realized it was anger. He was angry at Raj, and had no desire to see him, let alone eat lunch with him. But he couldn't remember why he was angry.

Leonard quickly cast his memory back over the past few days, few weeks even, but nothing out of the ordinary had happened. There had been work, and the usual game nights and dinners, but no fights (well, none other than trying to reason with Sheldon), no big issues. Just yesterday, in fact, Leonard and Raj had played a spirited one-on-one Halo tournament when Sheldon was engaged with his new issue of Green Lantern, and Howard had been busy taking his mother shopping.

No, there was no reason for Leonard to be upset with Raj. It must have been some strange dream, Leonard decided, that he was remembering fragments of.

Realizing that he'd been standing still for far too long in the middle of the cafeteria, he hastily continued his path to join his friends at their table.

"Your turn is up," Raj was telling Howard. "It's my turn now."

"But I've got a possible date lined up for next week," Howard argued. "I need it."

"Dude, when has the Time Machine ever helped you score with a chick?" Raj asked skeptically.

"There's a first time for everything."

"There are also schedules that prevent us from spiraling into chaos," Sheldon said. "And your time with the machine is up."

"Leonard, you're the primary owner, tell Howard it's my turn now," Raj said, turning to Leonard for support.

For a second Leonard felt the urge to take Howard's side, just to annoy Raj, but he remembered he had no reason to do that.

"Raj is right, Howard, you've had it for a month."

Howard scowled.

"Fine. Just remember that means you guys all have to help me move it. And my mother's trying this new diet, so she is not in a friendly mood."

"When is she ever?" Leonard asked with a small laugh, digging into his lunch at last.

Sitting with the guys, slipping into the conversation, Leonard was once again able to cast aside his strange feelings regarding Raj and just focus on the present. Nothing was wrong, and he was already finding it laughable that he thought he'd been so angry at Raj.

After lunch Leonard continued with his experiments, and at five o'clock on the dot met with Sheldon to return home. Sheldon talked about the remarkable progress he'd accomplished that day (as always), and Leonard only half-listened, adding only the smallest comments when needed to satisfy Sheldon.

Back at the apartment they checked their mail, dropped off their bags, and jumped on their laptops. Leonard aimlessly surfed the web until he ended up on Facebook. He had the feeling there was someone he wanted to check on, but he couldn't remember who, and a quick scan of his friends list didn't help either.

Deciding it must not have been very important, Leonard minimized his windows as Sheldon bid Amy farewell and ended their video chat (nearly a year had passed since their initial meeting, and they had yet to meet in person a second time), and the two roommates left for dinner.

Leonard turned automatically towards the left as he pulled out of the apartment's parking lot, and jumped when Sheldon asked sharply, "Where are you going?"

"To the restaurant," Leonard said, raising an eyebrow as he glanced at Sheldon. "It's Tuesday."

"I am quite aware of the day of the week. And Tuesday means we eat at Bob's Big Boy. Bob's Big Boy is to the right. You turned to the left. Therefore, you are not going to Bob's Big Boy."

"I... sorry." Leonard pulled into the left lane, and at the next light made a u-turn. "I don't know what I was thinking."

"Clearly you weren't thinking at all," Sheldon said.

Leonard ignored the slight - which was tame by Sheldon's standards, anyway - and continued to the restaurant, where Raj and Howard were already waiting for them. Leonard felt strangely as though it had been ages since he'd last been there, but at the same time he could remember eating there last week, and the same nearly every week before since he'd moved in with Sheldon.

They all ordered their usual. The feeling from that morning that something was wrong had resurfaced, and Leonard kept looking up around the restaurant, as if he was expecting to see someone. But no one else was meeting them there.

"Something wrong?" Raj finally asked, the third time they'd had to nudge Leonard to get his attention, which had been wandering elsewhere.

Leonard shook his head.

"It's been a long day,: he said. "I think I'm just tired."

He didn't feel like trying to explain what was wrong to them when he couldn't explain it to himself. After all, it had been a long day - even with the new pump, they hadn't been getting the results they'd expected, and that resulted in extra work to figure out why. But surely he'd get more sleep tonight, and tomorrow would be better.

Instead the next day brought more of the same. Once again, Leonard woke up, went to work, ate lunch with his friends... The same thing he did every day. But once again, he found it difficult to shake the feeling that something was off, something was missing.

Leonard became ever more frustrated as the day continued. Although he didn't had an eidetic memory such as Sheldon's, he did pride himself on having what he considered an above-average ability to recall. So the fact that he couldn't remember or place what it was that was wrong was grinding on his nerves.

That night Leonard picked up Chinese food and brought it back to the apartment for their weekly Halo tournament. He dropped the food on the table, half-halfheartedly responded to Sheldon's inquiries about his dinner order, and grabbed a soda from the fridge.

"Is someone else joining us?" Howard asked, divvying up the food.

"No, why?" Leonard asked as he sank into his normal spot in the armchair.

"You got more food than usual," Raj said, poking around in a bag. "Looks like there's enough for a fifth person."

Leonard frowned. Thinking back, he realized he had been thinking of five when he placed the order in the restaurant, but now he had no idea why.

"Now we're going to have extra food," Sheldon complained.

"Not if we eat it," Leonard said, regretting the comment before he'd even finished.

"And disrupt our digestive systems for the rest of the evening? I don't think so."

Leonard rolled his eyes but didn't argue. He was the one who'd accidentally bought extra food, after all.

"Who eats this anyway?" Howard asked, opening one of the boxes

Leonard took the box, glancing inside. He's positive that he ordered this dish specifically for someone, but he doesn't know who.

"Let's just eat so we can play," Leonard said, setting the dish aside and reaching for his own food. "I'm starving."

The extra food was never eaten. After all, their order had been perfected over the years, to provide the exact amount of food needed for each of them. They rarely deviated from their regulars, and when they did, even their alternate orders were carefully selected to ensure that everyone ate their fill yet there was little to none left over. Leonard had simply ordered too much food.

The others didn't dwell on it (though Sheldon did comment that he would have to rearrange the items in the fridge to make room for the extra food), but Leonard's eyes were constantly drawn to those untouched food containers. Who had he bought them for? And why did he feel now like there was someone missing, someone who should be eating that food?

After a couple rounds of Halo the troupe headed to the comic book store, and for once Leonard finally felt like everything was normal. The four of them, browsing the new selections, arguing over who found an issue first... This was how things were supposed to be.

As they climbed the stairs, new purchases clutched carefully in their hands, Leonard thought that maybe he was finally getting over whatever funk he'd been in over the past couple days.

"We'll be over this weekend to help move the time machine," Leonard told Howard later that night, as he and Raj were getting ready to finally return to their own homes.

"I really can't keep it just a little longer?" Howard asked. "I'm telling you, Stacy would love it."

"Stacy? What about Bernadette?" Leonard asked, flipping through one of his new comics.

"Who's Bernadette?" Howard asked. Leonard looked up in surprise to see that Raj and Sheldon were also looking at him with confused expressions.

"Bernadette," Leonard repeated. "She's your... she's..." He frowned, unable to explain himself. He had brought up her name naturally, automatically, yet now he didn't know why. "Weren't you dating a Bernadette?" he finally asked, sure that that was it. He could even almost picture her, a short blonde who was tougher than she looked (though Howard tended to stray towards blondes, so that wasn't saying much).

"No, I'm pretty sure I wasn't."

"Have you ever been tested for insanity, Leonard?" Sheldon asked, asking in what was for him a concerned tone. "I'm sure my mother would be able to assist you in finding someone to talk to."

"I'm fine, Sheldon." Leonard said. "Never mind."

Howard and Raj left, still looking confused about Leonard, and Leonard escaped to his bedroom, telling Sheldon he was going to call it an early night. What in the world was wrong with him?

Leonard dreaded going to work the next day. He knew exactly what it would contain - more of doing the same thing, and more of feeling like something was wrong. Although his anger at Raj had mostly faded, and certainly hadn't reappeared as strong as it had that first morning, he had still felt it creeping up at times, catching him by surprise.

And there was still the never-ending feeling that something was just plain missing. He looked around his bedroom before leaving for work, checking that everything was where it was supposed to be, hoping that maybe he'd find that he'd left his Stan Lee autographed comic book out instead of carefully put away, or maybe a spare DVD disc that had never found its way back to it's case... But everything was still where it should be, and he knew that what he was feeling was larger than any of those things.

He hurried to finish getting ready for work, and grabbed an untoasted bagel to eat when he got to his office. His inspection of his room had taken longer than he'd realized, and Sheldon was already out the door and heading down to the car. Not wanting to listen to Sheldon's complaints about Leonard's tardiness all day, Leonard took the steps two at a time going down, and nearly ran into someone as he turn the corner on the stairwell between the third and second floor.

"Sorry!" Leonard said, grabbing the woman's arm to prevent her from falling forward to the stairs below. He steadied himself, and finally looked up into her face to receive the biggest shock yet.

"Penny?"

"Leonard!" She gave a small smile. "In a rush to get somewhere?"

Leonard realized he was still grasping her arm, and hastily let go.

"Oh, um, yeah. To work. Sheldon's probably waiting in the car for me by now. And you, uh, are you - where are you going?" He was babbling, and he knew it, but he couldn't help it.

"To work," she said, taking a small step back to he could clearly see her Cheesecake Factory uniform.

"Oh, right." His brain was suddenly going a hundred miles an hour, but he couldn't think of a single thing to say.

"Well, I guess we should..." Penny motioned down the stairs.

"Yeah, right, right."

Leonard let her go first, and stayed a step behind her, not wanting to rush off. Sheldon could wait. He realized that Penny hadn't crossed his mind once in the past few days, and that was somehow puzzling to him. Penny was... just Penny.

His next door neighbor. And nothing more. She'd moved in a few years ago, and that had been that. Leonard had been interested, of course, but after an awkward introduction and greeting, he and Sheldon had simply retreated to their apartment. They crossed paths occasionally in the building, it was hard not to living on the same floor, but other than brief hellos and polite small talk, there had been no further interactions.

So why was it that Leonard felt such a huge draw towards her now? He'd thought - been certain - he had moved on from the little crush he'd nursed when she first moved in. He knew she'd never be interested in him, and had accepted that. Yet now he felt like he'd known her his whole life, like her absence was part of the reason the past few days had been so strange. It was like she was a missing puzzle piece that had finally fallen into place.

They didn't speak again until they got the to parking lot. Sheldon, as expected, was waiting in the car, and honked the horn when he saw Leonard exit the building.

"Guess I better not keep him waiting," Leonard said, yet he didn't walk towards his car just yet.

"Guess not." Penny bit her lip, and for a second Leonard thought she was going to say something more, but Sheldon honked the horn again, causing them both to jump slightly.

"See you around," she said instead, and with a small wave she turned to her car. Leonard watched her go, certain that somehow things had just become much more complicated.