The harsh sound of knocking stirred Penny from her chocolate-induced coma. She grunted. Picking up her head, she glared at the door. There was only one person on the planet who knocked like that.

"Penny?" Three knocks. "Penny?" Three knocks. "Penny?"

She weighed her options.

If she answered the door, Sheldon would demand things from her she wasn't interested in giving. If she didn't answer the door, he'd start knocking again. She didn't want to deal with him knocking more.

"Coming, Sheldon, one minute."

Sliding off the couch, Penny spared a glance at the floor to make sure it was passable. There was a box of pizza on the floor. Two slices were still inside. Two tubs of ice cream sat beside the pizza, each half-full of melted ice cream and candy chunks. Next to the ice cream tubs were several mostly eaten bags of chips, some spicy dip, and three bottles of beer.

Wincing, Penny made her way to the door.

If she was lucky, Sheldon would go blind the minute she opened the door.

She opened the door.

"What happened to your apartment?"

The universe hated her.

Sighing, Penny stepped aside to let him enter. "Nothing happened," she told him, lying half-heartedly. If he suspected she wasn't being truthful, he either didn't notice or wrote it off as her still being mostly asleep. Sheldon really didn't need to know that the previous night she had the world's worst argument with her dad. Who still wasn't over the fact that she wasn't attached to a penis. Bastard, she thought, though the word was only barely formed in her head.

As Sheldon strode into her apartment and began picking things up, Penny shut her door and leaned against it.

"Sheldon, what do you want?" she asked, in no mood to cater to him. She had every intention of passing out on her couch again as soon as he left.

Setting the ice cream tubs on the counter in her kitchen, Sheldon said, "I need a ride to the mall."

"Why's that?" she asked.

"Because I have been informed that Saint Nicholas will be in residence at the North Pole outside of Macy's."

Penny stared.

Sheldon continued to clean up her apartment.

"What did you just say?" she asked, slowly peeling herself off the door, hoping that she'd still be able to walk in her shock.

"I said that Saint Nicholas will be at the North Pole outside of Macy's." Sheldon gave her an assessing look. "When was the last time you had your ears checked, Penny? A woman of your age should not be experiencing aural problems."

Her ears were fine. Her ears were perfect. It was her brain, attempting to process Sheldon's absolutely impossible statement, that was the problem. Sheldon Cooper wanted to see Santa Claus. Sheldon I-Don't-Believe-In-Christmas Cooper. Wanted to see Santa Claus.

"You," she said slowly. "You want to see…" She trailed off, completely taken aback.

Sheldon rolled his eyes. "Yes, I do, and I require a ride."

Penny was half dressed before she knew it, pulling a red camisole on and then a button-up white blouse. The blouse, decorated on the collar with delicately embroidered ornaments, was understated. She had always hated ostentatious holiday clothes, but this shirt had appealed to her.

Going to her bathroom, she quickly washed her face and applied a bit of make up. She brushed her teeth, combed her hair, and worked it into a sloppy ponytail that would suffice for a trip to the mall.

Grabbing a pair of socks from her drawer, she strode from her room.

Sheldon had finished cleaning her apartment, and was perched on the edge of her couch. "Finally," he said, standing.

Running a hand over her hair, she frowned at him. "You really want to go to the mall. To see Santa Claus."

He stared at her as if she had grown a second head. "Of course."

"Can you at least explain this to me?" Penny asked as she attempted to merge left on the highway.

Some asshole blared his horn and flipped her the bird as he sped by her. She scowled and continued to merge.

"Explain what?" Sheldon inquired, turning her Christmas music down.

Penny turned it back up. "Why the hell you of all people want to see Santa Claus. You don't do Christmas," she responded.

"I don't celebrate Saturnalia," he said. "But Saint Nicholas, not Santa Claus, was a real man."

Her eyes widened and she took a quick glance in his direction. He was staring ahead, his face expressionless. "He was?" she asked.

The sigh he gave was long-suffering. "Yes. The popular culture creation of Santa Claus was inspired by Saint Nicholas of Myra," he said. "Saint Nicholas was known for his generosity toward the poor. In one story, he provided the dowries for three young women so that they wouldn't need to become prostitutes."

Penny's lips formed an "Oh," but she made no sound. "So… you accept him because he's…" She groped for intelligent words. "Because he's, like, historical?"

"Yes. There is historical support for Saint Nicholas," Sheldon agreed.

The two were silent for a while as Penny assimilated this. Her lips quirked. "What about him traveling around the world? Isn't that impossible?"

She never thought she would be in the position of arguing Santa Claus's implausibility to someone, especially a grown man.

"It's highly unlikely, but I'm sure Saint Nicholas has some way of doing it. He would need to travel faster than the speed of sound, and would have only a few seconds to deliver presents to every child." Sheldon paused. Then, "I must admit, I haven't thought about it in great detail, but it could make an interesting study."

Sheldon spent the remainder of the trip talking through his ideas regarding how fast Santa Claus would have to travel in order to make all his deliveries. He postulated that the man must have some sort of "anti-gravity" technology, because it was impossible for a single sleigh (and eight reindeer) to pull the approximate 300,000 tons.

Penny listened in disbelief. Sheldon Cooper was rationalizing Santa Claus. Of course, Sheldon Cooper's Santa Claus had Star Trek-esque technology that could do amazing things. At one point, he even speculated that Saint Nicholas was an alien who had traveled to Earth thousands of years ago in an attempt to teach humans how to be nice to each other.

Penny had no idea what to think about the whole thing. No idea at all.

She waited patiently in the line with Sheldon. She waited patiently when he went up to Santa. She – and everyone else, including Santa – was stunned when Sheldon actually sat on the man's knee. She suppressed her reaction and waited patiently as he told Santa Claus what he wanted for Christmas. She waited patiently when he stood, collected his coat and bag (which contained a book from Barnes and Noble about Saint Nicholas), and joined her at the exit.

She stared at him.

He stared back.

She broke with silence with a sputtered "You just sat on Santa's lap!" He didn't blink. "And you told him you wanted a… a—" She lost steam when she realized she didn't remember what Sheldon had asked for. "A what was it?"

"Large Hadron Collider," Sheldon supplied. "Like the one at CERN."

"Right, so you just told Santa you wanted CERN for Christmas." She stared at him for a long moment. "I still don't get how this works out." She frowned. "I don't. You spent the entire car ride and line explaining to me how Santa Claus could be plausible and real. And I don't get how you believe it."

Sheldon gave her a genuine smile – a real, genuine smile, not one of his scary as hell forced ones. "Everyone needs to believe in a little bit of magic," he told her.

Penny jerked, surprised. Her eyes widened and she stared at him, her heart melting. "Aw, honey, that's so sweet."

His smile vanished as though it never was, eaten up by one of his blank-faced expressions. "If they didn't, the bleakness of the human condition would be far too overwhelming."

Penny's forehead collided with the palm of her hand. Of course, Sheldon would have to ruin it.

They walked out of the mall, side-by-side, making their way to her car. Clouds darkened the sky. Penny stopped, peering up at the clouds. As she stood there, a little snowflake spiraled downward, landing on her nose. Her eyes crossed as she watched it melt.

And she wondered, quietly, to herself, if a person could ever really stop believing in just a little bit of magic, even if they devoted their life to proving that it wasn't real.

For Courtney_Beth, over at the Paradox livejournal com.