Phase I of the plan is to become an expert on anything and everything to do with Charles Augustus Magnussen.

For months, she follows him at a distance, gets a sense of his basic movements and habits. As she goes, she leaves behind a trail of sensors. She obtains access to the CCTV feeds outside his offices. She places cameras outside the perimeter of his residence at Appledore and outside the private airfield he frequents. (She nearly gets caught by his security more than once, leading to a few delightful chases and even an automobile accident or two.)

Magnussen is impressively repugnant. She watches him manipulate people, destroy lives. She takes copious notes and reports back to her employer regularly.

She begins identifying his employees, past and present. She monitors them, online and off. She makes the acquaintance of a few in real life, and creates a number of online identities to follow them on social networks (it’s amazing the details that people will casually reveal about their employers and places of work while thinking that they’re posting about their own lives).

Many of these turn out to be dead ends. She dates David, Magnussen’s driver, for two whole years. She quizzes him about work and places recording devices on his various possessions. But Magnussen travels only with his bodyguards and chooses not to confide in them -- at least not in the car. She’s relieved when David takes a new job and she can stop dating him; He is sweet, but very tiresome. His favorite hobby is being chivalrous and protecting her from things.

(Occasionally, she’s lonely. She fantasizes, fleetingly, about having a partner, a family -- despite the fact that she knows the hazards of caring. But it’s a safe fantasy, all very abstract, because she knows she couldn’t find real people to fill those roles. Not with hobbies like assassination, wire-tapping, week-long stakeouts, and near-fatal car crashes. People like David only prove to her how very far she is from normal. She’s insane, and well aware of it — but mostly, she’s happy enough. As happy as she can possibly be.)

Magnussen takes a long time to get to know. He’s very cautious. Secured lines, encrypted data, checking his meeting places for recording devices. (His frequent meetings at 10 Downing St. and other British government strongholds should be easily surveillable given her employer’s resources, but Magnussen is too canny.) He may be terrifyingly powerful, but that doesn’t seem to be making him careless.

If she wanted to kill him -- or, rather, if her employer wanted her to -- it would be easy enough. He’s not as careful with his personal safety, and she can take someone out from half a kilometer away. But, of course, that’s not what the man in gray is after. (Mr. Holmes, she reminds herself. She wonders sometimes if it’s his real name.)

Eventually, she gets impatient and decides to step things up.

* * *

“You shouldn’t be here.” He frowns at her as she enters the office deep within the Diogenes Club. He’s wearing navy. It throws her.

“I’m sorry, Mr. Holmes.” She’s not actually sorry. She’s curious. She looks around the office, which she’s heard about for years but never seen. “But you haven’t been responding to my messages.”

“You haven’t had any news worth responding to.”

“I sent you the information about his new safety deposit box. And his upcoming trip to East Asia.”

“Uninteresting. I already knew both facts.” He raises his eyebrows. “Try harder, Agent Morstan.”

It’s what she expected. “I think it’s time to start infiltrating his closest employees.” It’s more dangerous, but they’ve been hitting dead ends for too long.

“Do you have a target in mind?”

She nods. “Janine Hawkins.”

“The new PA? Bold.”

“She’s about my age. And wouldn’t you know it? We happen to use the same gym. Even chatted in the locker room, once or twice.” She grins.

His mouth makes a moue. “You didn’t wait for my approval to move ahead.”

She shrugs. “It was expedient to assume you’d agree with my analysis.” She mimics his speech style as she says it, grinning impertinently.

He steeples his fingers and makes what she knows is an attempt to look menacing. “Don’t grow overconfident, Agent Morstan. You should not visit me here. And you should not perform analyses when you don’t have all the relevant data. Your job is to bring me intelligence; mine is to make the decisions.”

She shrugs again. She’s a woman of action, and one he’s hired to do ludicrously dangerous things on a regular basis. He can hardly blame her if she takes action, or if she fails to be menaced by his stare.

He sighs. “Proceed. But don’t contact me in person again. Go through the proper channels, next time.”

She nods, trying to hide a triumphant grin. “Yeah, all right. Where’s the loo?” Primary mission accomplished, she might as well take the opportunity to explore a bit more, as long as she's here.

She follows Mr. Holmes' directions down the hall, then takes her time on the way back. As she nears his office, she’s surprised to hear raised voices. She pauses outside the door to listen, able to see only the smallest sliver of the room through the door hinge.

“Oh, no, of course you don’t have time to talk!” shouts the man who is not Mr. Holmes, pacing back and forth. “I guess it shouldn’t surprise me. Maybe if you’d had more time -- if you’d paid more attention when he was alive, he wouldn’t be d--" a pause, then, softer, "-- he'd still be here.”

“John, I am rather busy right now. Important matters, I assure you. If you’d like to make an appointment with my assistant --”

“Bullshit, important matters. It’s your fault he’s gone. What’s more important than that?”

She hears Mr. Holmes sigh. “John, whatever misguided attempt your therapist has been making to get you to talk to people from the past as part of moving on, it's rather pointless in this instance. I regret your loss, but I have nothing to say to you.”

“My loss? You heartless bastard. What the fuck is wrong with you? He was your brother.” Brother? It has never occurred to her that Mr. Holmes has a family, that he did not spring into existence in his current form. She tries to imagine him as a child and utterly fails. The best she can manage is an image of a smaller version of him, proportioned the same and clad in a three-piece suit, steepling his fingers and dispassionately threatening the safety of another child’s teddy bear if he fails to divulge desired information. And she can’t begin to fathom what his brother would be like. Still, she feels a sudden sadness for Mr. Holmes over the loss, hard though it is for her to conceive of.

“He was. And believe it or not, I deeply regret his absence. But that does not stop the needs of the nation. I’m going to have to ask you once more to leave.”

Mary slips out before she is spotted. But she lingers nearby, curious to get a better look at the man who dared to shout at Mr. Holmes.

There’s something about the compact blond man as he strides down the street that keeps her gaze. Something in his step, the set of his jaw, the way his hand flexes as if he’s replaying the conversation and imagining ending it with punches in place of words. At the corner, waiting to cross, he clasps his hands behind his back and stands at parade rest. He wears the most unassuming civilian garb yet radiates danger, like a tiger in an oatmeal jumper.

She wants to know everything about him.

Only because it could be valuable to her, of course, in her understanding of her employer. Who apparently has -- had -- a brother. A brother unlike him -- a brother who was capable of having friends. (Or lovers?) Neither of which she has ever seen evidence of in her years of knowing Mr. Holmes.

* * *

“Have you tried the yoga class here?” she asks, knowing the answer.

“What? Oh, hi -- you again!” Janine smiles. “Yeah, I have -- the instructor is rather good, actually. Are you thinking of going?”

“Yeah, I was. I’m terribly out of shape,” she lies, smiling.

Janine laughs. “Really? You look quite fit.”

“Bless!” They engage in the standard feminine dance of self-deprecation and body loathing. Then, hesitantly: “I don’t suppose you know if there’s good coffee somewhere around here?”

Janine looks surprised. “You new here, then?”

Mary laughs. “Yeah, still getting settled in. I keep meaning to explore the neighborhood, but first I was unpacking boxes, and then my life got eaten up by a book, and I just haven’t --”

“Oh yeah? Which book?”

Mary names a recent bestselling thriller, and Janine squeals with delight at the serendipity. “Oh my God, I just read that!”

Mary grins and pretends she didn’t already know this from looking at Janine’s library record. “Thank God, I’ve been dying to talk to someone about it!”

“Me too!”

Mary glances at her watch. “Are you free now? I’ll buy you a coffee if you’ll sit and talk for a bit.”

Janine checks the time on her phone, then frowns and and taps out a brief email. “Sorry,” she says, looking up as she finishes. “Demanding boss.”

“On a Sunday?” Mary widens her eyes.

“All the time,” Janine grins wryly. “But I’ve got a bit of time right now, actually -- and I can show you where to find the best coffee.”

They get along smashingly. By that evening, Mary has obtained from Janine a number of local restaurant recommendations, a list of books to read, a spa date for next week, an inventory of her purse, and a copy of all the data on her phone. Janine even parts with the majority of these items willingly. It’s the start of a great friendship.

* * *

The man behind the desk is staring out the window, his face utterly blank and still.

She knocks on his open door. “Hi. I’m here about the job posting?” she says, smiling tentatively. She has no intention of taking a job, but this is a perfect opportunity to find out more about the man who yelled at Mr. Holmes.

“Oh, right,” he looks up at her, then stands to shake her hand. “Come in. I’m John Watson.“

“Mary Morstan.”

He gestures to the chair in front of his desk. “Have a seat. I’d offer you a cuppa, but I’m afraid I’m just getting the clinic set up, and don’t even have a kettle in -- all I can offer you is water. Disgraceful, I know.”

“Oh, no, I’m fine, thank you.” She sits.

He sits back down as well. “Good. Good.” And then he smiles at her.

She wonders how she didn’t notice before that he’s a very attractive man. (Possibly it was the mustache, which doesn’t suit him.) She grins wide in response and stares him up and down. He laughs, and she realizes she’s missed whatever he just said.

“Sorry, what?”

“Most people don’t grin so suggestively when I ask them for their CV.” He smiles wider. “Is it such an interesting CV, then?” He raises his eyebrows and holds out his hand.

She hands him the piece of paper. “Nothing too scandalous, I’m afraid.”

“Pity,” he mutters, barely audible, scanning her fictional employment history.

“I don’t put the most scandalous bits on my public CV, actually.” She arches an eyebrow as he glances up at her.

“Oh, really? Well, maybe you should fill me in on some of the details of your private CV sometime, then.” He grins in a just joking but totally not joking way.

“Maybe I should.” She returns his smile, and it’s the most truthful thing she’s done in ages.

* * *

“You’ve taken a job,” Mr. Holmes observes. She’d hoped it would escape his notice for longer, knowing she was hoping in vain. And indeed, on her very first day she’d received notice that she was to meet him. In another condemned building, this time -- no more visits to the Diogenes Club for her.

“It’s just a part-time gig,” she says. “I thought it would make Janine relate to me better.” It’s true. The more she looked into the job opportunity, the more sensible this seemed.

“Nursing.” She nods. “At the clinic of one Doctor Watson.” His eyes narrow.

She nods. “Yes. He seems amenable to a flexible schedule, so I think I shouldn’t have any trouble getting away as needed.”

He stares at her a long time. “Purely a business relationships then, is it?”

He undoubtedly knows that her meeting John is not a coincidence -- quite likely knows exactly when and where she first encountered him -- but if he’s not going to bring it up, she’s not either. “Just coworkers, yes.”

“You’re having dinner with him tonight.”

She laughs. “You know, it’s creepy when you turn your powers against me.”

He ignores the deflection. “Why did you agree to meet him?”

She’s asked herself the same. “It’s a nice, normal thing to do. Go on a date. Something to talk to Janine about, next time we get coffee.” She smiles brightly, projecting innocence as best she can.

He smiles back, cold and tight-lipped. “I’ve spent years grooming you for this job. One of your primary advantages as an agent is your lack of attachments. Do not eliminate your usefulness.”

She laughs. “It’s just a lark. You know me -- I don’t have real friends.”

His eyes follow her knowingly as she takes her leave.

“By the way, Mr. Holmes,” she says, pausing on her way out, “I’m sorry about your brother.”

He doesn’t respond.

* * *

“Where did you live before London, then?” she asks John, after they’ve ordered their meal and poured the wine.

He looks wary. “I was at war, actually. In Afghanistan.”

“Ooh, sounds exciting!”

He laughs, startled. “That’s a new one. Pity’s more common. Sometimes anger.”

“Oh, sorry, I can probably do those -- just give me a moment,” she teases.

“No, that’s all right,” he smiles. Then he swallows. “It was exciting, actually.”

She nods. “Tell me all about it.”

He looks at her for a long moment, and then he does. He tells her war stories over dinner, getting more frank about both the terror and the excitement of the combat zone as they get closer to the bottom of the bottle of wine. She listens and asks questions and gently jokes with him when she sees that the honesty is becoming too overwhelming for him. And she regrets that she didn’t meet him during a time in her life when she could afford real relationships.

She invites him back to her place, and they have frantic sex. Then they have more measured sex. It’s been a long time since she’s slept with someone more than once. A long time since she has taken the time to learn someone’s body, to map out their responses. She finds herself enjoying it.

In the morning, he cooks her breakfast (well, he heats a tin of beans and makes toast), and they drive to the clinic together.

* * *

Ooh, sleeping with your boss? Janine texts during her lunch break, after Mary tells her who last night’s date was with. Since they traded numbers over coffee, they’ve been texting more days than not. Janine seems a bit lonely, which is a stroke of luck for Mary. Daring! Especially at a new job.

Oh, well, that’s me, you know. Living a life of danger.

Heh. How was it?

None of your business, nosy, Mary responds with a smile.

Must have been horrid, or you’d be bragging. I take it he’s lacking in certain departments.

Mary snorts. Actually, it was lovely. He’s lovely. And the sex was excellent. Every time.

:DDD You have to meet me for drinks after work and dish.

Mary is pleased with herself. It’s extremely easy to pretend friendship with Janine, and dating John is definitely going to help make her more relatable.

* * *

On their second date, she answers John’s questions about her childhood and early nursing career. She gets quiet as she talks about the car accident that killed her parents.

John squeezes her hand. “I’m so sorry. It’s very hard to lose someone that close.”

She wipes her eyes with her free hand and nods. “Have you? Lost someone?”

He sighs. “Yes. Just a bit over a year ago, actually. I’m still putting my life back together.”

“Tell me?” She squeezes his hand back.

He does, but just a little bit. “He was like nobody else. So brilliant. He could tell what you’d spent the day doing from the splatter of mud on your trouser cuff.”

It was genetic, then. (She’d always wondered how much of his older brother’s eerily accurate inferences were due to CCTV access.) She feigns skepticism, eliciting several tales of deductions and casework. “Fantastic!” she says, a number of times.

“I know.” John grins.

The most surprising piece of information that she gleans from the evening is that her employer sports the rather ridiculous first name of Mycroft. It’s possibly even more ludicrous than that of his deceased younger brother.

That night, after they have sex, he whispers, “Thank you,” in the dark.

“Mm?” Mary is already slipping toward sleep.

“This is the first time I’ve been happy. Since.” His breath hitches. “For a while.” She listens to his jagged breathing and smooths his hair until he sleeps.

* * *

How’s your dishy doctor?

Good.

Good? That’s it??

C’mon. Albert and I are on the outs again -- I’m depending on you for saucy tales! Tell me more about him.

I think he may be the saddest person I ever met.

Christ, you’re the worst friend -- that’s not helping me at all.

Want to meet for yoga and then tell me more after?

Yeah. Cheers.

* * *

John doesn’t have much else in his life besides the clinic, his therapist, and her. No family (mother dead, father out of the picture -- much like her, though of course she can’t say so; relationship with sister strained at best), no friends that he’s particularly kept up with (occasionally he sees Mike or Greg, but it’s very occasional). He and Mary end up spending the evening together after many of her shifts.

As they spend more time together, she grows more impressed by how broken he is, and by how well he mostly hides it. All day long, he smiles and jokes with patients, does paperwork, and runs errands with a calm efficiency. At night, alone with her, he’s funny, attentive, sweet. But interspersed with all of it -- especially when he thinks nobody is watching -- his face will suddenly become the saddest thing she’s ever seen. And sometimes something small, something seemingly innocuous, causes him unexpected pain.

She suggests, once, that they go see the circus, and he makes an anguished sound. It takes ages and several drinks for her to pull the story out of him of a previous circus date (and she’s not sure she has it straight, in the end; the Chinese gangster plot doesn’t make much sense). Once she has, she realizes that despite the apparent danger to his life and his girlfriend’s, the thing he’s most fixated on is how Sherlock brazenly invited himself along on John’s date. How John enjoyed having Sherlock along (despite his protests) and adored him for his very lack of boundaries; how Sherlock brought excitement into every corner of John’s formerly monotone life. John shakes as he talks about it.

* * *

She reads up on dating widowers. And suicide survivors.

* * *

Once she’s gotten him started, John won’t stop talking about Sherlock. She’s happy to listen -- fascinated by the stories of the cases they solved, but equally fascinated by the intensity of the relationship John describes.

Alcohol is the key to getting John to open up. “It’s funny,” he muses one night at her flat. He’s propped up on one elbow, leaning against her sofa, utterly relaxed and open. He looks at her through slightly unfocused eyes. “You’ve never asked if we were sleeping together. People always used to assume. Even the blog readers assumed.”

She had wondered, at first. “The way you described him, I thought maybe he was asexual.”

John laughs humorlessly. “Yeah, he might have been. I don’t know. He was my best friend -- and I was his only friend -- and I still don’t have a clue if he’d ever had sex. Or if he wanted to.”

“Would it have made a difference if he had wanted to?”

He closes his eyes for a long time, and she thinks he isn’t going to answer. Finally, “I’m not gay.” Clearly, she thinks, but doesn’t interrupt. “So for a long time, I never really thought about it -- except when people would assume, and I’d be irritated at them for being so sure they understood how it was.

“But. Well. I’ve never really been interested in men. But. He wasn’t like any man I’ve ever known. And what I had with him wasn’t like any friendship I’ve ever had. And sometimes, since. Yeah, I’ve thought maybe. Maybe it would have made a difference. If he wanted that.”

She aches for him, wishes he’d realized in time to do something about it. Wishes it would have helped, would have stopped Sherlock from committing the senseless act that has filled John with such deep sadness.

Simultaneously, she’s fiercely glad that John is here now, with her.

* * *

You listened to him talking about his ex all night again, didn’t you?

It’s not like that.

Mary feels vaguely guilty that she even told Janine about Sherlock’s death. It feels to private to John. It’s also basically impossible to talk about John without talking about Sherlock, though.

Tell him to talk to his therapist. This isn’t your job.

No, it’s fine. I want him to talk to me about it.

You’re totally falling for him, aren’t you?

Mary stares at her screen for a long time.

...you there?

Fuck, I am, aren’t I?

Yep.

Fuck.

* * *

At first, the lying didn’t bother her. She’s always been of the opinion that not knowing everything about other people is the key to happiness, and she has never minded lying for work. She adores her job like she has never adored any person in her adult life, and she knows most people would be horrified by the fact that she occasionally kills people. So it’s never been a hard choice.

She feels that balance shifting, and lying becomes more inconvenient. And mildly troubling. Besides, knowing John’s priorities, he might be happier if he did know all about her dangerous side, so that’s no excuse.

Overall, she’s less bothered by the lying itself than the idea that John might find out.

* * * 

One night, months later, John is distant. Brooding.

She asks what’s wrong; he deflects. She changes the subject, asks him to tell her about how he met Sherlock; he withdraws even further. She gives up and suggests they see a film.

After the film and some whisky, he apologizes and admits to her that he feels guilty. Guilty for talking so much to her about Sherlock. Guilty for missing him so much, for thinking about him constantly, still. “Even when.” He swallows. “Even when I have you. Even when I’m with you. All the time, I wish he were still here.”

Mary nods. “Of course you do. You loved him, didn’t you. You don’t forget someone like that. Not ever.”

He sighs. “It’s not fair, though. To you.”

She shakes her head. “It’s all right. I don’t expect you to turn it off.” John looks skeptical, and she searches for words. “He’s… he’s a part of you. You missing him is a part of you. And I care about all of you, including that part. I really don’t mind.”

It’s true. She often thinks that she couldn't compete with the real Sherlock Holmes, if he were still here (at least Nurse Mary, the Mary that John is allowed to know about, couldn’t). But she’s perfectly content to share John with his memory.

He smiles at her. “You’re amazing, you know that?” he says. Then, after a hesitation, “I love you, you know.”

“Of course I know,” she says with a grin. “I love you, too.” For the moment, the discussion is set aside in favor of other activities.

Later that night, lying in bed, John says quietly, “I did love him. I’ve never said so, in those words. But it’s true, I suppose. I just wish he’d known.”

“I’m sure he did know.”

John laughs bitterly. “You didn’t know him. He was shite at emotions.” He goes quiet for a long moment. When he does speak again, he’s barely audible. “I don’t know what’s worse -- hoping that he did know, and that he didn’t jump because he thought I didn’t care, didn’t believe in him. Or hoping that he didn’t know, so that I don’t have to wonder why he left me, if he knew how much I cared.” His voice cracks.

She strokes his hair for a while.

“Most often, I think he didn’t know. So many times when I might have said...” He trails off and sighs. She pulls him closer, wraps herself around him.

* * *

She hails a cab and finds Anthea waiting when she gets in. It happens, from time to time; it wouldn’t do for her to be seen climbing into Mycroft’s car, obviously. (The driver of the cab is, of course, Mycroft’s.) Mycroft texts her on a dedicated mobile when the message is simple. When it’s more complicated, but he’s too busy to meet in person -- off doing whatever it is that Mycrofts do -- he sends Anthea with the message.

“You’re still seeing the doctor,” Anthea comments, not looking up from her phone.

“Yes.”

Now Anthea looks at her, cocks an eyebrow. “Risky behavior.”

Mary shrugs with feigned nonchalance. “Mr. Holmes recruited me because I like risks.”

“You’re talking about moving in together, aren’t you? Mr. Holmes won’t like that.”

“I know.”

Anthea smiles, then turns thoughtful. “He won’t stop you, I think.”

“Of course he won’t,” she says confidently, belying the relief warming her chest.

“If it were anyone else, he might. But he feels indebted toward Doctor Watson. Guilty, too, I think.”

“Guilty?” Anthea only shrugs.

Perhaps Mycroft does feel some responsibility for the death of his brother, then. When John had laid out for her what had preceded Sherlock’s suicide, she had been convinced that Mycroft had some long con in mind when he’d leaked information about Sherlock to Moriarty. Mycroft is infinitely crafty, and never careless. But even if he did have a plan in mind, it had gone awry, and Sherlock had suffered the terrible consequences. As had John. And, all evidence to the contrary, Mycroft apparently experiences feelings -- or at least guilt.

“What do you see in Doctor Watson?” Anthea asks, curiously. “I always thought he was a bit dull. He must be more interesting than I’d realized, to capture your attention.”

Mary thinks about it for a while. Anthea is the only person besides Mycroft who knows what she really is, and out of the two of them, the only one she’s likely to confide in, especially about this. “He’s interesting. And he’s sharp. And he needs me. But mostly, I feel safe with him. He’s someone else who understands the thrill of danger. Someone who will kill when necessary. I can be myself with him.”

Anthea laughs at that, and after a moment, Mary joins in.

“So what’s the message?” Mary asks, finally.

“It’s time to deliver some bait,” Anthea tells her.

* * * 

Sorry, she texts Janine from the clinic. Have to cancel our spa day on Friday -- you’ve been trumped.

Hot date?

Not this time. My stupid MP cousin is having a fancy do, and he made me promise to come. She hits send, then adds, I think he feels obligated to introduce me around, but I’m sure it’ll be all political talk and dull as bollocks.

I didn’t know you had a cousin in Parliament.

I’m ashamed to be related to him -- he’s a Tory.

Ugh, I can’t believe you’re standing me up for a Tory! You owe me.

Why don’t I buy you dinner next week to make up for it?

You’re on. Have fun with the Tories in the meantime.

Vomit.

Bait delivered.

“You free tonight?” John asks, poking his head out of his office.

She looks up from her phone. “Who wants to know?”

“A certain doctor who I hear is rather smitten with you,” he says.

“Ooh, is he handsome?”

“Well, I think so, anyway.”

She pouts. “You think he’s handsome? That’s a shame, because I’m rather smitten with you, actually -- I don’t want any doctors turning your head.”

He tsks, trying to suppress laughter. “Oh dear, this is quite the love triangle we’ve got here. We should discuss how to resolve it over drinks.”

“I like the way you think.” They giggle at their ridiculousness as they lock up the clinic.