Prompt from orangesherbert06 over on tumblr. I hope I did it justice!
Molly always came in for Sherlock, because he called her when he wanted her to come in. Sherlock hardly ever texted her—he had her text him quite often, but he always called or found her in person. There was one memorable night where she hadn't answered her phone—she'd been deeply asleep in the midst of what she thought was a bad cold—and he'd broken into her flat to find her. He'd softly called her name in the darkness of her living room, getting a bit louder as he went to her room.
"Sherlock, you let all the cold air in," she'd whined when he came into her room, tucking herself deeper into her comforter to hide from the 'cold' and from the light he flicked on. The weight at the side of her bed was odd, as were the hands which gently pried her from her little cocoon. Molly shivered and moaned out a protest as Sherlock brought her up to lean on her headboard, and she'd sniffled as pathetically as she could to try and generate some pity for herself in his questioning blue eyes.
Sherlock had taken off his gloves and took her pulse, leaning in with the same motion to lay his lips on her forehead for a moment. Molly had stilled in shock, trying to curb her shivers in the icy room as well as those from where Sherlock touched her. When he leaned back slightly, he put his forehead against hers.
"I didn't let all the cold air in, Molly, you have a fever. Do you have anything that you like to take to alleviate the symptoms?"
He hadn't had her come in that night, instead sitting at her side on the edge of her bed and supervising her sleep and medicine regimen. Molly had been woken at dutiful four hour intervals for her pills, and before he'd left in the morning he had made her a rich chicken broth and made sure she ate it. The only 'not good' thing he'd done was left the kettle on as a sort of alarm clock before he'd gone.
Things had changed a bit when he'd gotten a flatmate, but not by much. Sherlock still called her or found her if he needed her, but she was less of a sounding board now than she had been. He had his other friend now, and that was okay with Molly. She was honestly quite happy that Sherlock had found someone to be real friends with, because while they were friendly to one another she was sure that Sherlock didn't consider her his friend.
But still, he did things that only close friends might do for one another—she wouldn't let herself assume that he was at all interested in her because she knew him—like when he escorted her home early one night. She'd been fighting off a cold for more than a week, which wasn't fair because it was summer, and Sherlock had wrapped her up in the coat he'd worn to the lab. The heavy thing wasn't something to be worn during the day, but Sherlock had arrived at the lab at half four in the morning and had needed it at the time. In the cab he had the driver turn the heat way up and let Molly doze as she would—it was rush hour and it would take a goodly long time to get to her flat. She'd thought that until she looked up at where he'd shuffled them out of the cab.
"Sherlock, you took us to your flat."
"Indeed. You're in need of a doctor with that burgeoning pneumonia, and I know just the man."
Molly had scoffed, cuddling deeper into his coat, and tried to remember which way it was to her house or to the main road to catch a cab. Sherlock had rolled his eyes in response, finding her elbows in the great swath of fabric that was his greatcoat and bringing her close. His lips found her forehead, pressing what could only be a kiss there for several seconds longer than Molly thought necessary.
"You'll have the fever by tomorrow morning, best to nip it in the bud. Don't want to ruin your summer with being stuck in hospital."
She must have been sick because she had a bit of grump to get out at him.
"I'm always stuck in hospital—I work at one, Sherlock."
"Well this is different and you know it. Come up, I texted John to tell him you were coming."
She'd woken up the next morning—John had listened to her lungs and said that without an x-ray he couldn't be one hundred percent about it, but yes, she had pneumonia and that he'd get her the prescriptions she needed in the morning—very warm. The room around her was icy, but where she was under the blankets she was gloriously warm. It was almost as if she had a huge heater installed along her whole body—she was in bed.
She was at Sherlock's and in bed.
And there was a heater behind her.
Molly had dared to brave the icy air around herself and turned to look over her shoulder—having found herself fairly well contained by long, lanky arms—at Sherlock Holmes who was sleeping soundly, wrapped around her to the best of his ability. It took some doing, but she managed to turn over enough to press her face against his chest. His collarbone was a nice place to put her poor nose so that it didn't freeze in the cold of his flat.
"John left about a half hour ago to get your medications. I think he might have even called Mycroft to pull some strings," Sherlock said—apparently not as asleep as she'd thought—flexing his arms to hold her tighter. Molly nodded just a bit and listened to his breathing. And then she pushed away from Sherlock just enough to scoot up a foot or so and laid a kiss on his forehead.
"I think that you're going to get ill, Sherlock." She reached up to comb her fingers through his hair, scratching his scalp just the tiniest bit with her nails.
"Mm, will have gotten it from you. Did last time."
"Kissing people to diagnose fevers is rubbish, by the way."
His blue eyes popped open and sought hers.
"Who says I was diagnosing a fever when I did it?"