Disclaimer: This fan fiction is not written for profit and no infringement of copyright is intended. Not beta read, so all mistakes are mine. Thanks for their reviews go to razzle-dazzle1606, Crimson and Chrome 42, Hana, Emmapocalypse and koryandrs: Cheers lads. And now, on with the story...

I DO BUT SING BECAUSE I MUST

Sherlock doesn't really remember the first time he met Mrs. Hudson.

He thinks that he was nineteen or maybe twenty, in the first blush of those wandering years between getting turfed out of Oxford and over-dosing in Camden. Everything a blur, a new set of experiences for him to try. A new set of grownup trials for him to screw up. He used to use a dealer called Caspian who lived a couple of doors down from 221B, the elder brother of a university friend. Caspian sold the strongest, cleanest, most organic drugs in Central London to boys like himself and girls like his girlfriend, relieving his university chums of the need to go into the nastier parts of the city in order to score and simultaneously keeping himself in the sort of style to which his Daddy's money had allowed him to become accustomed.

It was, he liked to tell everyone, a win-win situation.

Sherlock didn't like Caspian, or his girlfriend Portia, but he did like knowing his drugs weren't cut with anything dangerous. He was not yet at that stage of addiction where the desire for oblivion had morphed into the desire for self-annihilation, and drugs like those Caspian sold meant he could stay reasonably safe. So he'd come around maybe twice a week with a pocketful of money and sit on the steps of 221B, waiting for Caspian to come out to him. It was far more dangerous doing a deal in the open but Portia- the girlfriend- refused to have Sherlock in the house ever since the night he drunkenly offered to suck her boyfriend off if he knocked something off the price of his order. (Sherlock didn't know what she was so upset about; he was hardly the first one to offer.) But be that as it may, Portia was dead set against him with a hardness of heart which would have done Queen Victoria proud. And so Holmes sat on the steps of a house he didn't know and waited for his friendly, neighbourhood drug-dealer, trying his best not to look suspicious.

And since he usually sat on the steps of her house, unsurprisingly, he ended up running into Mrs. Hudson quite a lot. Ended up talking to her too.

He wasn't yet living on the streets at that point and his clean clothes and upper-class accent put her at her ease enough that she didn't chase him off her step. And so an entente of sorts began. A truce. But as the months went by, he began to notice certain things about her. Even through the blur of being perpetually stoned he saw that her appearance changed quite radically, that sometimes she wore elegant, dressy clothes and sometimes she came out swathed in more fabric than a mummy. She also wore sunglasses a lot, despite the fact that winter in London is seldom sunny, and she seemed accident-prone, if the amount of bruises he saw on her were any indication. At first this had confused him: Were he to see her today, Sherlock would have known within minutes of meeting her that she was being physically abused by her husband. The signs were all there; it was practically text-book. But he was young and she was proud and they never talked about it. He was just The Boy On The Step and she was just The Nice Lady Who Smiled At Him. They had no other connection than that, nothing else in common.

And then, after a more than two years of this arrangement, he discovered that Mr. Hudson was on trial for murdering a young woman in Florida.

He found out because he overheard her in the hall, talking to someone on the telephone through a door she hadn't locked properly, and she sounded absolutely terrified that her husband would escape the charges and come back to her.

By that time Sherlock' addiction had turned more serious, the weight falling off him, his contact with the real world becoming ever more tenuous. He was waking up in strange beds with strange people and even stranger bruises, and he'd lost all contact with Mycroft, though his brother continued to deposit money in his account every week. Sherlock knew he was falling, losing himself to the substances he took. They no longer dulled his mind but dulled his senses, and he found himself waking up some days wondering whether he was alive at all. But something about the idea that The Nice Lady Who Smiled At Him might need his help seemed to cut through the fog of his dependence. The skills he'd polished all through his teenaged years, the skills which had made him such an outcast in university, those skills could, he knew, rescue The Nice Lady Who Smiled At Him. And so he'd haltingly introduced himself and offered to help ensure her husband's conviction. She'd been nervous but not frightened, and while it had been obvious that she didn't believe him, she'd still offered to buy him a cup of tea in Speedy's, and maybe a sandwich, a ritual which had eventually become weekly until Sherlock finally kicked his habit once and for all. And he had managed to ensure her husband was convicted of the murder, his first proper case working with Gregg Lestrade, the case which convinced him he could be something besides his need for stimulation-

He thinks of all this as he sits in his front room now, Mrs. Hudson fiddling in her lap with the long sleeves of her top.

He thinks it and he remembers her bruises and he thinks about the one he saw on Molly Hooper today, and it doesn't happen very often but Sherlock realises that he'd really, really, really like to shoot something Right. The Hell. Now.

"You talked to John," he says then, because really, why else would she be here?

He came in to find her already in the flat, pouring herself a cup of tea.

The older woman nods, her eyes going anywhere but his. He hasn't seen her look this nervous since her husband's execution and despite himself he feels an unaccountable flash of annoyance at it. Doesn't she know she has nothing to fear from him?

The memory of Molly's reaction today flashes behind his eyes and he forces the thought away.

She must see his irritation though because she seems to pull herself together, gestures for him to sit. She's brought a plate of biscuits out- bourbon crèmes- and if she's eating those then she really is nervous.

But then, given what Sherlock suspects they're about to talk about, he supposes he shouldn't be surprised.

"John called and told me what you think's happening," she says then, taking a biscuit and dipping it into her tea. Another nervous habit. "He says- He says you think someone's hurting our Molly."

"Somebody is." Realising that there's no way he can get out of this conversation without being so unspeakably rude even he'd feel ashamed of himself, Sherlock nods and folds his lanky frame into the chair opposite her. He takes a biscuit and waits while she pours him a cup, chewing thoughtfully until the tea is ready.

"Is it that Ollie?" Mrs. Hudson asks, and her hands shake ever so slightly as she says it. The colour in her cheeks turning high even as the rest of her skin pales. It doesn't happen often, but just for a moment Sherlock feels tempted to… comfort her somehow.

He sighs though. He's really not built for that sort of thing.

"I think so. Statistically speaking, it's more than likely her domestic partner." He grimaces. "You of all people know that."

She nods. "And do you think- How far along is it?" She clears her throat and makes a show of staring into her teacup, taking a bite of her biscuit. "I mean- Do you- Do you think he's…"

"I know he's grabbed her by the throat," Sherlock says curtly. "I suspect he's done more- Now that I think about it, the amount of time she's spent out of work is suspicious. She was healthy as a horse when I lived with her; she never called in sick. But these last few months…"

Mrs. Hudson nods again. "And the way she acts around you and John now," she says softly. "I think- I think he's probably told her to stay away from you two. You especially, Sherlock." Something hard and angry twists her lip. "Men like him don't like the notion of competition."

Sherlock snorts. "I'm hardly competition. If Ollie's insecure enough to believe that then he's an idiot." He shakes his head at himself. "Though he's not the only one. I can't believe I didn't see this-"

"Sherlock." Mrs. Hudson doesn't often use that brusque, no-nonsense tone, but she's using it now. It always makes Sherlock feel… mothered.

He'll never admit how much he likes that.

"You know you couldn't have guessed this," the older woman is saying. "I didn't see it, and I of all of you should have known. But I always thought Molly so sensible- except for her little crush on you- and she seemed so genuinely happy in the beginning. I didn't want to spoil it, and just because something horrible happened to me doesn't mean it will happen to everyone, you know?" She shakes her head to herself, plops her cup down into her saucer slightly harder than she strictly needs to. Again her mouth twists into that angry, hard line. "I should have seen this," she's muttering, "I really should have seen this…"

She sighs. "But I didn't. Nobody did. And all we can do is try to help Molly now."

And for the first time in a long time, Mrs. Hudson looks old.

Sherlock nods, rather than ponder that. He really doesn't like contemplating his landlady's progressing age. "Of course," he says instead. "I take it Molly can stay here if she needs to?" Mrs. Hudson looks almost affronted that he'd felt he had to ask. "Good. Then I'm going to go to Scotland Yard tomorrow and ask Lestrade to look into this Ollie. I'll need any info I can get my hands on, but I suspect the new Mrs. Watson will be more than forthcoming with that. And I'm going to talk to Sally Donovan about the best way to build a case-"

Mrs. Hudson's expression shows a twinge of disgust. "Why on Earth would you talk to that nasty Donovan?" she asks. "Didn't she and that Anderson get you into trouble before you faked your death?"

Sherlock shrugs. "Sally did three years with a Community Safety Unit in Brixton," he points out. "If anyone would know how to build a case, she would. Can't afford to hold what she did against her if she's going to help Molly now."

Mrs. Hudson smiles at him, a warm, proud smile, and just for a moment Sherlock is The Boy On The Step again, having someone be nice to him for the first time in what seems like a lifetime. It's a surprisingly satisfying feeling.

"You're a good man, Sherlock Holmes," she says quietly. "A very good man."

"Thank you. I-I hope that will be enough." Sherlock looks down at his biscuit, not entirely certain how to respond beyond that. Knowing only that Mrs. Hudson's words make him feel better than he has since Molly stopped talking to him. So he swallows his pride and calls Lestrade that very night, gets Donovan's number and calls her-

He thinks this will be the beginning of the end for this case.

But as Sherlock soon finds out, his troubles have just begun.