One

On the last Saturday evening in March, the weather in London proved to be particularly nasty. Rain poured down in buckets, and the dark clouds above occasionally lit up with lightning, followed by booming thunder. But inside 221B Baker Street, all was warm and dry. Two people sat on opposite ends of the leather sofa in the sitting room. Each was eating out of a carton of Chinese food with chopsticks, and the both of them were watching an episode of "Strictly Come Dancing" on the telly.

"Appalling!" Sherlock exclaimed the moment the televised waltz routine had finished, even as the televised audience roared with enthusiastic approval. "Utterly appalling!"

Molly chuckled. "It looked pretty good to me," she said.

"You have an untrained eye," said Sherlock, but looked at her when he realized how that could sound. "I mean in terms of ballroom dancing, Molly."

"And when, in your career as a consulting detective, did you have to develop this kind of trained eye?" asked Molly, half teasing and half curious.

"Never," Sherlock replied, looking intently at the food in his container. "I took lessons for three years."

Molly couldn't help but give a small smile at this. It seemed like she learned something new about him each Saturday evening that they got together to just hang out. This had started when the new year had: any Saturday evening that Molly didn't work or Sherlock didn't have a case, they would hang out at 221B with takeaway and crap telly. And it had been a long road for the both of them to this point…

It had been a year and two weeks since Tom had passed away, and Molly still missed him every day. But her support system of friends had never wavered and only grown stronger. Where it had grown stronger was not only becoming closer to the Watsons, Mrs. Hudson and Lestrade: it was finally having something she could truly and without a doubt call friendship with Sherlock. Since their early morning conversation in Kensington Gardens eleven months ago, a lot of rebuilding had been done between the two, including building that had never been done.

For the first few months, Molly had kept Sherlock safely at arm's length, keeping their relationship purely professional. The only times that they would see each other outside of St. Bart's were when they saw the Watson family for the occasional dinner.

Then, when the leaves on the trees turned from green to gold, Molly began to trust him more, going with him on cases when John couldn't or preferred to be with his family. But the Christmas and New Year's holidays had been the true turning point; loving company, heartfelt gifts and the true spirit of the holidays had done wonders for the pathologist.

Being reminded of how truly blessed she was had given her the courage to finally be able to call Sherlock a friend. And for the past three months, their friendship had blossomed and was still growing strong…

"Who had the idea to put you in dance class?" asked Molly, smiling a bit at the thought of a young Sherlock in a ballroom dancing classroom.

"My father," Sherlock replied. "I was a very energetic child, often having more energy than I knew what to do with. Since I did not really get along with other boys my age because of our differed interests and my…well, my unique personality –"

Molly snorted and Sherlock shot her a glare before he continued.

"Well, for those reasons, sports were never a good option for expounding my energy. So, my father suggested dancing lessons."

"How old were you?"

"I took lessons from age ten to thirteen. I stopped when puberty began because…well, I had a whole new set of worries and being around even more girls than necessary…and it just didn't help."

Molly had to bite her fist to keep from laughing out loud as Sherlock stuttered through his response and the tips of his ears turned bright pink.

Trying to redeem himself, he finished in a firmer tone: "But I've never forgotten what I learned. And just one year of dance class experience is enough to know that that waltz was a clumsy debacle."

Molly held up her hands in surrender. "All right, all right, I'll take your word for it. Since you know more than they do, would you demonstrate for me what a proper waltz step is, then? I'd like to know for future critiques."

Sherlock muted the commercial now playing on the telly, and spent a few minutes on his mobile until a pretty piano waltz played on it. Setting the device down on the coffee table, and ensuring that the volume was high enough to be heard over the pouring rain outside. Sherlock stood up from the sofa, walked around the coffee table until he was in front of Molly, and held out a hand to her. Molly looked at it in surprise and confusion before Sherlock explained, in a tone softer than it was sharp:

"I can't do a waltz without a partner, Molly."

For a moment, Molly felt frozen in hesitation, an old fear rekindling her chest. But in the next moment, she'd pushed it aside as silly, took his hand, and stood up. He then led her to the middle of the sitting room.

"Um, Sherlock, haven't you yet deduced that I am a complete klutz?" Molly asked as he put her left hand on his shoulder.

"Not a complete one, Molly," he said, his right hand settling on her back, his right arm supporting her left arm in the process. "Otherwise you would have many more broken limbs in your medical history. I've deduced that you are coordinated enough to handle a simple waltz with a partner who knows exactly what he's doing."

A statement like this would annoy most and offend some. Molly Hooper just laughed, causing Sherlock to smile. Bringing up their joined hands, Sherlock instructed: "Simply put, the basic waltz step is all in the rhythm of the music. 1-2-3 over and over again. If you let yourself become naturally attuned to that steady rhythm, like a pulse or a heartbeat, you can very easily master the basic step."

Molly nodded, his instructions making sense.

"Now, your first step is moving your right foot back. No!" He exclaimed the last word when he saw Molly lower her head to look at her feet. She looked back up and he spoke in a gentler tone. "Don't watch your feet. You'll lose the rhythm and your concentration that way. You need to trust yourself and your partner to accomplish a dance together. So just…keep eye contact with me, all right?"

His words seemed to become more weighted as he went on, his tone softening as well. Molly found that she could find no words, so she just nodded and held his hand a bit more securely. So she stepped back on her right foot, and he mirrored her by stepping forward on his left foot.

"Good, now step to the left with your left foot for the second beat. And for the third beat, move your right foot left to bring your feet together."

Molly nodded, and did as he instructed. His own steps mirrored hers.

"Very good. Now, for the next count of three, we'll switch steps and do what our partner has just done. So, step forward with your left foot on the first –"

"Then right with my right and then bring them back together again?"

"Exactly."

So they did the next three steps, and Molly kept eye contact with Sherlock. She couldn't resist smiling proudly to herself when they were done. Sherlock chuckled in response.

"Excellent, Molly. Now let's just repeat that simple sequence of steps in place to the rhythm of the music until you feel comfortable."

Molly couldn't help but notice that she already felt comfortable, quite comfortable in fact, considering their position and close proximity. But she shoved this thought aside and nodded her assent.

After counting to three to the rhythm, the two began to dance the simple box step of the rhythm. Molly moved a bit awkwardly at first, not nearly as smoothly or surely as Sherlock did. But the longer they repeated those simple steps, with Sherlock making sure that they did not stray from the box that they'd outlined with their steps, the more Molly got used to it. Sherlock's advice had been sound: just letting the gentle piano-played waltz wash over her and enter her subconscious made it much easier. Eventually, Molly no longer felt the insecurity to break Sherlock's gaze to look at her feet. She didn't know which was more to blame for that: her own growing confidence in the steps, or the reassuring and steady gaze of Sherlock's that held her own.

Eventually, Sherlock seemed satisfied with her progress and said, "Well done, Molly. Now, let's try moving around a bit more so we're not just stuck in one place. So, each time we do the sequence, we'll move a bit clockwise, all right?"

Molly gave an uneasy laugh. "Well, I'm sorry for your toes in advance, Sherlock."

Sherlock chuckled, and he guided them in the steps, this time turning them slightly to the right in the process.

For a while, Molly got through the more sweeping steps, awkwardly but without stepping on any toes. But then, Molly (inevitably, in her own mind) tripped over her own foot and fell forward. Sherlock, of course, was right there to catch her in his arms.

The air around the two of them suddenly became very charged, what with Sherlock's arms supporting her and Molly's head and hands resting on his chest. His heartbeat was strong and accelerated in his chest, and Molly was pretty sure that her own was, too. Holding her breath, Molly turned her face up so that she could look at the detective. His pupils were dilated, so much so that she saw more black than blue.

"Molly…" he said softly, his breath hot on her face. Molly felt her cheeks begin to burn and her heart practically pound against her ribcage now. Was it just her imagination, or was his face getting closer to her own?

The charged moment was then quite rudely interrupted by the sound of Molly's mobile both ringing and vibrating at full volume from her trouser pocket. It startled Molly so much that she jumped back and out of Sherlock's hold as if he'd been on fire. Thankfully, she landed with a thud on her own two feet. The detective, for his part just as startled as her, managed to keep his feet on the ground. His arms remained loosely open, and the look on his face suggested that he was perplexed and saddened that they were now empty.

Turning away from this unnerving sight, Molly fished out her mobile. The caller ID read that her boss, Mike Stamford, was calling.

She answered with a slightly high-pitched: "Hi, Mike! What's up?"

"Hey, Molly. Look, I'm really sorry about this, but Eric had to leave due to a family emergency. I know it's a Saturday evening, but could you come in and finish his shift?"

"Oh, um, of course! I can come in, no problem! I can be there in, um, twenty minutes. That okay?"

"Thanks, Molly, you're a real lifesaver! I'll hold down the fort until then. See you soon!"

"Bye, Mike," said Molly before ending the call and pocketing her mobile again.

She mustered up the courage to look at Sherlock again. He was now standing by the coffee table, typing out a text on his mobile. She vaguely noted that the pretty waltz music had stopped. When he was finished, he looked at her with a neutral expression. "I've sent for a taxi."

Obviously he'd gotten the jest of the call, and Molly suddenly felt uncomfortably guilty. "I'm sorry, Sherlock," she said sincerely. "I should have told Mike that I was busy. I'm just so used to going in whenever there's an emergency like this –"

Sherlock held up a hand. "Don't, Molly, it's fine."

"You don't mind?" she asked, not quite convinced.

"Molly, you're needed elsewhere. It's not as if we were doing anything…more important." The last two words were mumbled more than spoken, and to his shoes rather than her face.

She still didn't feel quite satisfied, but after that interrupted moment between them, Molly felt like she really needed to clear her head. Getting away from Sherlock, working until midnight, and then sleeping in the next morning sounded like a very good idea right now. But the last thing she wanted was to leave Sherlock on an awkward note. Their good friendship meant a lot to her, and she wouldn't let it go for the world.

"I'll make it up to you, Sherlock. If I can get any spare body parts, or if anything interesting comes through, I'll let you know."

He gave her a small smile. "I know you will, Molly. Please stop worrying, everything is fine." He looked towards the window and gave a satisfied nod. "It seems that the storm has dissipated. Go downstairs and wait for the cab."

Knowing that she would have to accept that, Molly nodded and returned his small smile. She gathered her things, put on her spring coat, and left the flat. Sherlock then walked to the window and watched until the cab arrived and Molly departed in it; the calmer weather and the glow of the nearby streetlamp gave him a clear view. But before she got in the cab, she turned her head and looked up at the window to 221B, where Sherlock was standing. Their eyes met for only a moment before Molly ducked inside the cab.

While Sherlock collapsed onto his sofa and curled up into a ball, and Molly leaned her head back against the backseat cushion in the cab, one thing was clear in both of their minds: a shift had occurred, and something had changed between them. But there was a difference as well:

While Sherlock dearly hoped it was for better, Molly was terrified that it could be for worse.