Molly woke up because something was unusual.
You would think it was being entangled with the worlds only consulting detective wearing nothing but scull-patterned underwear but still not shivering because as cold and marble-like his skin looked, he was actually really warm. You could also think it was because there was a severed hand in a bucket full of clear liquid next to Sherlock's side of the bed, but it wasn't that. She was used to these things. Well used to she still woke up in awe to find that she didn't dream that she was with him. She still didn't exactly know how it came, that Sherlock Holmes, the man she had loved since he came rushing through the swing doors of her morgue so many years ago, came to love her. And he did, he told her. It turned out, when you actually get to Sherlock's heart, he will never fail to remind you and apart from not understanding some basic things like why it was not ok to put lungs in the microwave next to the milk she was heating up he was actually the sweetest boyfriend. All this went through Molly's mind but she still didn't know why she woke up. Then she looked out of the window.
"Sherlock! It's snowing!" She jumped out of the bed and nearly jumped right back in when her naked feet met the cold wooden floor. Quickly she put on some woollen socks she found lying around and trousers as well as a t-shirt and a thick jumper.
Sherlock hadn't moved. She knew he was awake. He always was even though he was polite enough to not wake her up unless he wanted some… affection. Molly blushed at the thought of last night.
"Sherlock! It's real snow! Get up! PLEASEEEE!" The sight of snow had transformed Molly into a five year old. Always had always would. Snow for her was the best thing that water could be, except for hot tea when you come back home after a long day playing in the snow!
"SHERLOCK!" He still hadn't moved more than opening his eyes and watching her get ready.
"I really don't see the appeal." It is frozen water. You can't even put the crystals under a microscope before they melt." He propped himself up, so he leaned against the head of the bed. He was only wearing night blue boxers and the scar on his shoulder (the only one left from his fall and a silent reminder of how Molly had saved him) was clearly visible shining even paler than his skin.
"Come on you grump! You can't possibly compare observing things under a microscope to making snow angels and snowmen!" Molly was still whirling around the bedroom and walk in closet, putting on layer over layer of clothing and sometimes throwing things for Sherlock to wear on the bed. She had found out some time ago that this method was most effective if you wanted him to actually put on clothes. Throw them at him so he didn't have to get them himself
"I don't have reference for those kind of activities. Why would I want to throw myself into a heap of frozen water crystals?"
Molly stopped mid-movement while putting on a knitted-beanie she got for Christmas from Lestrade a few years ago.
"You've never played in the snow" Molly looked at him like he said he never had a cup of tea. "You need to. I demand it! Get dressed. NOW!" Sherlock groaned, but he still reached for the clothes that were in the heap on his bed. The purple shirt, dress pants. Socks. His scarf and his coat were in the hallway.
Half an hour later they were on their way to the next park. It was still snowing heavily and they couldn't see further than a few meters. Sherlock wore his coat, blue scarf and black leather gloves. He had refused to wear any hat but did turn up the collar of his coat. Molly wore her knitted hat and a matching scarf and mittens. She was holding his hand and pulling him along like a child would. Sherlock smiled into his scarf. She was so different from the mousy pathologist he had met years ago. Him needing her help with Moriarty's game was the best thing that could have happened for the both of them. It had made Sherlock realise how much he cared about all of his friends (and especially Molly) and Molly had grown so much. Mentally of course, she was still the petite little woman she was before, but with a completely different attitude.
They had reached the park by now, which was completely empty. Probably because it was 11am on Tuesday and all the children who would play were in school, or preschool.
Sherlock still didn't know what they were supposed to do. Molly had let go of his hand and run a few steps ahead. Now grinning from ear to ear, her nose red from the cold. He closed his eyes to catalogue this moment his mind palace, which was increasingly turning into a gallery of moments with Molly. Then something hard and cold hit him square in his face. Surprised he opened his eyes slipping into "fight mode" as John jokingly called it, expecting an attacker. But he just saw Molly laughing, another snowball in her hand. She hadn't recovered fully from her laughing-fit when a perfectly formed snowball hit her shoulder.
"That's the spirit!" she smiled, raising her voice so he could hear her over the distance and the snow that was so swallowing most of the sound around them. Then she ran towards him dodging another of his attacks and hurling her second ball at him, missing him by almost 2 feet. She wanted to just stop right in front of him, but slipped a little on the snow and fell right into his arms.
"Whoa careful!" his smooth baritone caught her just as much as his arms around her back did. " You wouldn't want to… fall into the snow would you?" And with that he pushed her away from him and straight into the snowdrift next to them, giggling like a maniac.
"You little…!" She didn't even finish the sentence when she felt him lying down next to her in the snow. He was just close enough so their hands touched. He turned and propped him self on one arm, so he could face her
"You know" His voice and expression were warm, so unlike the self-proclaimed sociopath he used to be "this is rather nice."
They spent the next few hours making snow-angels,
"Where are their arms supposed to be?"
Building a snowman,
"He doesn't even have legs! Those snow-things are really not anatomically correct!"
And finally drawing a giant, (finally anatomically correct) heart into the snow and writing their initials into it
"That would hurt a lot."
When they finally returned to Bakerstreet, with blue lips and red noses, John looked at them like they were ghosts. When he asked what happened to them and why they were all wet, they just broke into laughter and sipped on their respective mugs with tea. John was left answerless and wondering how one tiny person can turn Sherlock Holmes, world's only consulting detective and high functioning sociopath, into giggling, snowy mess and cuddling next to the fire-place kind of guy.