He slips back into the old flat like a man slipping into an old coat. All the things in his bedroom are exactly where he left them three years ago. A sentimental gesture on Sherlock's part? Possibly. Or possibly Sherlock couldn't be bothered getting rid of them, which seems more likely given that everything is covered by a thick layer of papers, books, and other detritus. Sherlock has never quite gotten the hang of the idea of a single-purpose room, and without constant monitoring will inevitably expand his possessions to fill any available space.

He cleans it all away. Papers into the filing cabinets (he should probably buy another one next time he's out, these are getting overstuffed again). Books on the shelves (by topic and then by date of publication, because Sherlock finds alphabetizing tedious). Anything still in evidence bags into a box, which he will take to New Scotland Yard in a few days. Anything that's an obvious biohazard gets binned. Then he changes the sheets, undresses, and gets into bed.

Quite an ordinary summer night in Baker Street, really.

The only real change is that the actual listed occupant of the flat is not in his normal position (in the lounge, glaring at something). That's because he's unconscious and heavily sedated in hospital after his second round of emergency surgeries in as many weeks.

And the reason Sherlock's there and John is here? The woman who put a bullet into Sherlock's chest but somehow managed to destroy John's heart? The stranger, the woman he doesn't know, the murderess who had disguised herself as the unexpected love of his life?

Mary. Or whatever her name is.

Physically, she's probably in her bed (their bed) in Hampstead. It's so late it's early, she had an eventful day, and she's sleeping a lot more now that she's pregnant. But she's also in a thumb drive on the side table in the lounge, waiting for him to plug it into the computer and meet her. And she's in his head.

He has absolutely no idea what to do about that.

He fetches his clothes and some papers from the house. It goes badly. Mary (or whatever her name is) tries to talk with him, and all he can manage to do is shout. At some point, feeling as though his face is alight, he screams at her, "Are you even a fucking nurse?" which is entirely irrelevant, but she's wearing her scrubs and he needs to scream about something, anything.

He can actually see the words break something in her, just before she spits back "Yes. Yes I am a fucking nurse. Since you manage to be a fucking doctor and a fucking thug at the same time I don't see why you think other people can't have multiple careers."

It keeps on from that point but is hardly a productive dialogue. They have never really had a fight before: minor tiffs, certainly, but in general they just had gotten on well and relied on the natural desire to see the other one happy to get over any disagreements. Clearly, they've been missing out on an undiscovered natural talent, since they go at it like professionals, fighting dirty, wanting to see blood.

That's the hell of it. If he didn't love her (it's easy to admit in his mind even if it's always been hard to say) he wouldn't want to hurt her now. To make her feel like he feels.

He quits his job, giving no notice, and signs up with his old locum agency. For someone who was once such a promising medical student he's beginning to have an extremely patchy CV. It's better than having to see her every day.

He goes to visit Sherlock in the evenings. At first these are brief visits, with his friend wandering in a chemically-mediated haze. But then, Sherlock's much-derided "transport" shows the same vitality that has enabled him to survive an awful diet, purposeful insomnia, a cocaine habit, and enough cigarettes to fumigate most of London.

It's a routine miracle, but Sherlock begins to recover.

He starts bringing takeaway dinners and board games. Sherlock, after some grumbling, develops a real fondness for playing Dominion. The man is actually verbally thankful for the food, which is a nonroutinemiracle. They don't talk all that much, but then they've never needed to.

One night he comes in bearing doner kebabs to find his friend engaged in poring through a large box of brightly colored cards. Sherlock glances up, smiles, and says, "Ah, John. Look! The Dark Ages expansion pack!"

"Nice. Who brought that for you?"

"Mary Watson."

Sherlock says this in the same neutral tone as he would say "Molly Hooper" or "Jeremy Lestrade." He feels a muscle clench in his jaw, but replies quite calmly, "She visits you?"

"As you know, she doesn't work Wednesday afternoons, and so she drops by after her rounds."

Still entirely nonchalant, but of course the goal is to see what his reaction will be. John, suddenly, finds himself angry. Not exactly an unusual state for him these days, but bloody hell if he isn't sick and tired of all the people in his life who are genetically incapable of being straightforward.

"And you don't mind this at all?" he asks.

"She is a client," Sherlock says, as if that explains everything.

"She shot you."

"Which I admit has not been my favorite experience. But given the circumstances it was an appropriate if not ideal decision for her to make."

"APPROPRI-" and he's shouting again, fuck. "Right. So. Everything's fine, then, we're all best friends with the serial killer."

"Well, those of us in the trade distinguish the contract or otherwise professional killer from the serial killer, although I do admit it's a blurry line since financial gain is often among the motivations for repeated murder. And honestly, reading over her files, I'm not quite sure where I will docket her in my index. There's a commonly used argument that murder in the service of one's country is-"

Sherlock is actually lecturing, and he has to break in.

"Wait, what? You've read that file? How?"

"I stole the drive from your pocket, copied it when you went to the bathroom, then put it back. Really John, have you ever met me? Of course I read it."

He scrubs his hands over his face, trying to compose himself and failing. "I haven't."

"I know."

Sherlock doesn't make eye contact. He never does, when obliged to deal with the softer emotions. His fingers, swollen from IV fluids and steroids, sort nervily through the cards.

"I am not in love with Mary, and perhaps that makes it easier for me to forgive her. But I have done. And I do intend to address this issue of Magnusson as soon as I can conveniently manage it. And then-" he sighs. "I suppose it's up to the two of you. But you could do far worse."

"Don't see how."

"Oh, please. Do you know how many people want to shoot me? I'm just glad my first time was with a friend."

He laughs, because it's better than crying. Sherlock pats his shoulder heavily, twice, because he's got no idea how humans behave and presumably someone did that to him in the past and he hasn't deleted it.

They eat their kebabs and play the game.

He gets drunk. It seems like a good idea.

Around three in the morning he and the Macallan have another good idea and dial Mary's number. It rings and rings and goes to voicemail, so he hangs up, but then she calls him back ten seconds later.

"John?" she asks. Her voice is choked with sleep and he takes another drink and wonders if he might be dying or not. He finds he doesn't much care.

"What sort of scent did you wear? When you were her?"

"Are you drunk?"

It's not really a question and so he doesn't answer.

"I. Am trying to find out. What that woman was like? The woman. You. Before I knew you. Back when you only shot people I hadn't met."

Silence. Then "Are you reading the file right now?"

"I am not reading the fucking file, and I haven't read the fucking file, and I want to know if you wore this damn Claire De La Lune muck or if it's all part of the act." The moon-shaped bottle is sitting at his elbow, and he knocks it to the floor, wanting to smell it, wanting to drown in flowers.

It doesn't break or spill. Nothing really works right for him.

She sighs.

"I'm pretty sure they only invented Claire De La Lune two or three years ago. I remember seeing the commercials for it."

"So what did you use? Sherlock made me learn to identify the fifty top perfumes, maybe it was something I like." He feels that this is a cutting remark, although he's not entirely sure how, and he doesn't want to tell her how badly he'd done on that quiz.

"I didn't have one particular perfume. I wore a different one every day. I probably had… a hundred? Or so. I sorted them into categories and would choose one based on how I was feeling. Bit of an expensive thing to collect, had to give it up now that I make less, but there you are."

That seems like something his Mary would do. She has dozens of scarves, and a massive selection of spices takes up two shelves in their kitchen. He can picture her, in some foreign country, doing terrible things, but still, somehow, her. Collecting and sorting little things when she's anxious.

"So- when you. When you stopped. Was it just - changing jobs?"

"No. The worst way to go undercover is to insist on holding on to any particular identifying traits. So I changed a fair bit."

"Like what?" It's honest curiosity, but the whiskey and a low-grade dread are roiling just below his breastbone.

"Oh, um. Well? I guess I used to like to run."

"Run what?"

She chuckles softly. "No, just run. I did about twenty-five miles a week on an ordinary week, and I'd try to do a marathon every year – though I couldn't always manage that. But I did loads of halfs and 10k races too."

"You like to swim."

"Yeah, now. Then I ran. "

"What else?"

"I wasn't a vegetarian back then. Though honestly that was just inertia and I probably would have changed over eventually anyway. I always liked animals and I had a hard time reconciling that with eating them. I couldn't keep a cat since I traveled so much. I listened to different music. Tom Petty and Mark Knopfler and stuff like that."

"I love Mark Knopfler!" The liquor and the content of the conversation give him the dizzy feeling of chatting her up in a bar.

"I know. I had a bunch of the same albums you do."

He sits in the dark lounge, listening to her breathe, not knowing what he wants to know. She goes on.

"I had a bit of surgery, before I came here. Just changed my nose enough to fool facial recognition scanners. I used to dye my hair auburn, too."

He had already known about the nose job, oddly enough… the scars are tiny and well-hidden but he is a doctor and knows what they mean. He'd never mentioned that he'd noticed them because he didn't care and because he's never met a woman who responds well to observations of her physical flaws. And he knows that her hair is colored, obviously. That isn't a secret. He'd actually helped her with that once and fucked it up royally, though in fairness they'd both been a bit drunk and extremely kissy throughout the process.

But the rest of it- it's nothing that would put him off (unlike being an assassin, for example) but it's nothing like Mary. Mary likes cats to the point she actually fosters the fucking things. Mary listens to Enya and Norah Jones. Mary swims and will cook him meat meals but will never, ever eat them. This woman is a stranger and can't fit in the category in his head marked "Wife".

He asks, slurring a bit, "D'you miss it? Your old life?"

With no delay, she replies, "No. I mean, at first, it was difficult to adjust. But then- the life that I made here - it was good. It was the sort of life I might have had if I'd made different choices. Better choices. And then you came along and…"

"And what?"

"I was happy. Really happy. I never lied about that." He can hear tears in her voice. He'd never seen her cry until she and Sherlock pulled him out of a bonfire and now she seems to do it all the time.

He listens to her breathing, sipping the last of the whiskey, which doesn't taste like much of anything anymore. Eventually she clears her throat and says, "I saw that you paid the mortgage this month."

Had he? Wait, yes he had.

"I knew you'd have a hard time coming up with that much on your own."

"Thank you. It was kind."

"Oh, no worries," he says, and holy Christ, he's at the Australian stage of drunk.

"Did you pay it because you want to come back?" she asks. There's hope in her voice and he's really had far too much to drink and he's so tempted to say "Yes" and go to Hampstead and put all of this miserable shit back in some locked room in whatever poor excuse he has for a mind palace and turn the key.

"I don't know." That's really all he can say and not be a liar.

Two breaths.

"Right."

"Yeah."

"I've got work in a few hours. Don't – drink any more, please? I'm really not worth it."

"I'll be the judge of that, madam," he says, grandly, but the Macallan is gone and there's nowhere he is going but bed. Or sofa, really. The seventeen steps that lead to his room might as well be Everest.

"I love you."

"Good night, Mary."