Penny and Sheldon are slowly getting to know each other.

He glanced at her dashboard with trepidation. "Penny, your check engine light is on."

She nodded. "I know. It's been on since I bought it."

He looked at her in horror. "Have you not gotten it looked at?"

Penny shook her head. "I looked at it myself. It's a short in the wire."

"How can you be sure," he asked nervously. "Are you a mechanic?"

Penny glanced at him with a frown. "No. But I know engines. I rebuilt a tractor when I was 12. I fixed all the cars and trucks on my family's farm when I was growing up. Heck, I took shop class instead of nursing in high school. I once put together a 1975 Ford Mustang 11 engine all by myself. Trust me, it's just a bad wire."

Sheldon snorted. "If it's just a wire, why not fix it?"

Penny gritted her teeth, beginning to regret inviting him. No matter how appealing he was. "Because it's a lot of work for something that doesn't matter," she almost growled. "You can't just reach in, pull it out, and then shove another in it's place. It's a bit more complicated than replacing a shoelace."

Sheldon pinched his right thigh to try and stop himself from talking. He knew he was annoying her, and he didn't want her to regret inviting him out. He looked out the side window and tried to think of something to say that wouldn't sound so much like a criticism. "How did you discover the Cheesecake Factory?"

Penny glanced at him. "I work there. Which means I know how clean the kitchen is. I don't eat out much, because you never know if the kitchen or staff are dirty or not. Here, I know exactly what's going on in the back, so I know I can eat the food without worry."

Sheldon looked at her with surprise. "I am impressed. Considering the state of your apartment, I would not have thought you would care about such things."

Penny wasn't sure if that was a jab at her or not. "Does my apartment bother you so much?"

Sheldon blushed and looked down at his hands. Penny pulled into the lot and parked. She looked at him briefly before getting out. Sheldon followed her into the restaurant, a bit wary of this unknown establishment.

Penny didn't bother with the hostess, just waved in a friendly manner as she breezed on by, and led him to a small table in a corner. Sheldon looked around at the décor, noting how popular this place was, if the many patrons eating was any indication. A waitress appeared and handed them menus. Penny didn't bother to open hers. "Bacon, BBQ cheeseburger with sweet potato fries and sweet tea, please."

Sheldon looked at Penny and then handed his menu back to the waitress. "For me as well, please."

The waitress nodded and walked away with the menus. Penny smiled and tilted her head. "So, what did you do over the weekend?"

Sheldon cleared his throat and smoothed a napkin over his lap. "I have been working on my theories of how sub-atomic particles move."

Penny frowned a bit. "You're string thingies right?"

He looked at her, appalled. "String thingies?"

Penny blushed and looked away. "Sorry. I got that wrong, huh?"

Sheldon began explain exactly what sub-atomic particles were. He paused when the waitress brought over their drinks and looked at Penny. Her eyes were glazed and a bit lost looking.

After a second she shook her head. "I'm sorry, Sheldon. I just don't understand it."

Once again he wondered how he could have the slightest interest in someone so much less intelligent than himself. In his agitation he spoke without thinking. "Considering the entropy that is your apartment, I am not surprised you have little interest in order and energy," he muttered.

He flushed a deep red and cringed, waiting on the inevitable explosion of anger.

"Sheldon, would it help if I cleaned up according to that chart you made?"

He looked at her in surprise. She didn't appear to be angry. If anything she was curious. Their waitress appeared with their food and he waited until she left to reply. "I could help if you want," he offered softly.

"Do you have OCD?" Penny asked.

He shook his head. "I have never been diagnosis as such. I dislike disorder. Things have a proper place, and I am uncomfortable when they are not in it."

Penny picked up a fry and ate it. She nodded slowly, as if making a big decision finally. "Well, after we eat, we can go back and you can go over the chart with me again. I'll try to abide by it."

Giddy pleasure ran though him, and he leaned forward eagerly. "I look forward to it," he said.

Penny laughed lightly. "Eat first, plan later."

Sheldon picked up his burger and took a bite. It was better than the burgers he got at Big Boy. The rest of the meal was spent talking about generalities.

Sheldon was in the process of reorganizing her kitchen cupboards (really? Soup bowls stacked on top of tea cups?) when there was a knock on the front door. Penny had left to pick up pizzas for them so he hesitantly walked over and peered out the peep hole. All he could see was blond hair, so he opened the door curiously.

"May I help you?" he asked the diminutive woman looked at him curiously.

She smiled widely. "I doubt it. I'm Penny's ..friend. Bernadette Rostenkowski. You must be Sheldon Cooper." Bernie bit the inside of her lip as she hung up her coat. She had almost said producer, and that would have spilled the beans on Penny's real career.

Sheldon immediately stepped to the side and shut the door. He looked over Penny's girlfriend carefully. He felt a surge of competitiveness and tried to tamp it down. This was the person Penny had chosen to be with. He had no business feeling jealous.

Bernadette looked around the apartment in astonishment. "Oh my!" She looked back at Sheldon. "Does Penny know you're doing this? You know what happened the last time," she warned.

Sheldon blushed and shuffled back to the kitchen. "Yes. She will be back very soon. She left for pizza. I am helping her reorganize her living space."

Bernadette walked over and hopped up onto a stool in front of the island. Her legs swung rhythmically as she leaned her chin on her clasped hands. "So, Penny says you're some kind of genius guy."

Sheldon felt a surge of pleasure that Penny had mentioned him to her girlfriend. "I am a theoretical physicist at Cal-tech. And yes, I am a genius."

Bernadette's falsetto giggle covered the sound of the front door opening. Neither of them noticed Penny enter the apartment. She looked at her two friends curiously. Bernie was giggling, and Sheldon was blushing lightly. Penny's eyes grew wide. She felt as if she was intruding on something intimate.

Bernie looked over before she could decide what to do about it, and hopped down. "Hey," she smiled as she took the drinks and bag of garlic bread from Penny.

Penny smiled at her friend before turning toward Sheldon, who was staring at them intently as if he was upset. Penny placed the pizza on the counter and looked up at him with concern. "What's wrong, sugar?"

Sheldon looked down at his shoes. "Nothing. I was just wondering if you and your girlfriend would prefer to dine alone. I don't want to be a 'third wheel' if you have plans together."

Penny's jaw dropped and she heard Bernie burst into loud peals of laughter. "Sheldon, Bernadette and I are just friends. Best friends, granted, but we're both straight."

Sheldon looked up quickly, reading honesty and amusement in Penny's expression. "Oh. I apologize. I assumed from our earlier conversation you and Bernadette were involved in some way. You mentioned that you have a standing date every weekend to be together."

Penny blushed as she realized the implications. "Sorry about that. I didn't mean it the way it sounded. Bernie and I have been friends for years. I met her when I was in junior rodeo back in Omaha. Her dad is a huge rodeo fan and on a hunting trip he dragged the whole family to an event. I met Bernie when she got separated from her dad and ended up wandering into the paddock."

Bernie laughed musically. "I was more scared of the huge bulls than I was of being lost. This one snorted and bumped the gate and I screamed. A group of girls laughed at me and Penny came to my rescue."

"I never did like Cheryl," Penny muttered. "Vapid, slutty princess."

Bernadette patted Penny's shoulder consolingly. "She let me hang out with her until the end of the rodeo. She won 2nd place in calf roping and 1st in barrel racing."

Penny grinned with pride. "It was a good day. Two awards, and a new best friend." Sheldon placed plates on the table and opened the pizza boxes. He froze when Penny walked around him, and patted his arm. "Kind of like today. A clean apartment and a new close friend."

Bernadette smiled to herself as she watched the attraction in Sheldon flare in his eyes. He covered it up almost immediately, but he wasn't quick enough. She already knew Penny had at least a little bit of interest in the tall scientist. Now she just had to wait for them to realize their feelings were mutual.