Sherlock paused. He stood on the sidewalk, stock-still as the crisp winter wind bit at his cheeks (half-hidden by the upturned collar on his signature black coat) and ruffled the blue scarf around his neck. His dark curly hair blew restlessly in the breeze. He closed his brilliantly blue eyes, listening to the sounds of the evening. He was the image of serenity.

Yet something was not right. He scanned his surroundings. He saw nothing out of the ordinary; a bench and a streetlight to his right, some apartment buildings along his left. A young couple was strolling casually down the street. They laughed and chatted easily.

That won't last long, Sherlock thought, somewhat annoyed. I mean, look at the man's tie. He's obviously cheating on her. From the shoes- goodness, how can she not have seen that?

He turned away from the couple, slightly satisfied at the small bit of deduction he'd made. He turned his attention back to the matter at hand- what was wrong? It wasn't anything right in front of him. He spun in a sow circle, scanning the area for unnatural goings-on. Nothing. Or, at least, that he could tell, but he was usually right about these things, so he kept looking.

He glanced at the buildings to his left. It was an apartment complex, a relatively old one. Something connected in Sherlock's brain. Molly lives here, doesn't she? He looked up to her window and froze. That was it. That was what was wrong. He rushed to the door, where, by unbelievable luck, an older woman was coming out the door.

"Have you seen Molly Hooper recently?" he asked her, one hand on the door.

"I'm afraid I haven't, young man," she said sweetly. "The last time I saw her was this morning. Wait a moment- aren't you that famous-" But she didn't get the opportunity to finish her sentence. The tall man had barged past her, sprinting up the stairs to the floor on which Molly resided.

On his way up, his mind was racing. No signs of a forced entry, he thought. Nor anything showing a struggle. Could they have sedated her? Possibly come in through another entry? I can't be sure; Moriarty and his lackeys are exceptionally clever.

When he got to her door, he pounded on it. "Molly!" he shouted. "Molly! Open the door!" He was sweating a bit on the back of his neck, despite the chill from outside.

Abruptly the door opened. Inside the flat stood one very annoyed Molly Hooper, wearing an adorable, if not incredibly dorky, Christmas sweater. She held her cat in her arms and wore an aggravated expression which melted as soon as she saw that the one bothering her this late was none other than her favorite consulting detective. The frown returned when she remembered that he was the one who had rudely deduced the heck out of her new boyfriend just that morning and reduced her to tears, when all she'd shown him was a low-quality photo on her mobile. (Actually, Sherlock had been using it without permission, and he's happened to stumble across the picture.) All in all, Molly was not exactly pleased to see him, although she couldn't help it when her heart fluttered a bit at the sight of him.

She tried to be stern, yet affectionate with her voice, and it didn't really sound that professional. "Sherlock?" she asked. "What are you doing here? Back to remind me exactly how Robert is cheating on me?" She was very surprised when Sherlock did not shoot a witty comeback at her as usual, but looked somewhat confused.

"Molly?" he asked. "Are you all right? Has anything happened to you tonight?" He looked her up and down, scanning for any signs of injury. "Nobody has entered into your residence or done anything to harm you in any way?"

"Of course not," she said. "What makes you think that?"

Sherlock mumbled something inaudibly as his face became slightly pink and he looked away.

"What is it, Sherlock?"

"The Christmas lights," he admitted. "In the window. They weren't on."

"Your point?"

"My point is that every day, from the beginning of December to mid-January, you have had the same red, white, and green Christmas lights turned on in your window from the moment you arrive home, until you retire for the night. You've had them the exact same way for three years. I was passing by, and I noticed that, for the first time, said lights were not lit, though your main lights were still on, indicating that you had not gone to bed yet. There was a break in a continual pattern, and I simply assumed the worst: that you had been somehow incapacitated and were unable to turn the lights on." Molly understood; just recently, she'd dumped Jim, who turned out to be James Moriarty, a psychotic murderer. It was plenty possible he'd attempt some form of revenge on her.

Yet Molly just stared at him. "You… remembered?" she said.

"What do you mean?" Sherlock answered, puzzled.

"I mean, you remembered about my Christmas lights. I thought nobody ever noticed them. But you did."

"Of course, I did. I am exceptionally observant."

"And you were worried about me."

Sherlock was taken aback. "What? I- of course not. I just wanted to prevent anything that could harm you from happening. There was nothing sentimental about it."

"If there wasn't some sort of emotion there, how come you were banging on my door in the night like a psychopath, waking up the neighbors?"

"High-functioning sociopath," Sherlock said automatically. "And… that was instinctual. I had little control over my body's reactions to a possibly dangerous situation."

Molly smiled. Watching a man who didn't understand feelings in the least attempt to explain his own was rather funny. "In any case," she said, "thank you for noticing my lights. I'm glad someone is getting a little cheer out of them. I suppose I completely forgot about it tonight, but I'll go plug them in now. Would you like to come in?"

"No, thank you," Sherlock said, attempting to be polite. "I must be getting back to 221B. I'm in the middle of an experiment that requires my attention." He paused. "Oh, and Molly? I must apologize for my actions earlier today. I understand they were inappropriate for the situation." He turned swiftly and, his black coat swirling behind him, stalked away.

Molly watched him go. If there was one man in the universe who could tear out your heart, then be kind and make you fall for him all over again, all in a single day, it was a certain Sherlock Holmes.

"John, do we own any Christmas lights?"