John's phone rang, buzzing lightly against his chest in the inner pocket of his coat. Juggling the takeaway coffee and pastry, he managed to fish out his mobile. The park bench was cold through his trousers, but gave him somewhere to put his things down and keep out of the way of the early morning runners and cyclists.

"Greg?" he answered. "What is it?"

"It's Amanda, actually," a woman's voice said on the other end of the line. "Hassard. Sorry to catch you off guard like that; I thought you'd be more likely to answer a familiar number."

"It's all right," John assured her quickly. "Is everything okay? Is it Greg?"

"What? No, he's fine, glaring at me like normal. Listen, John, I know it's really early in the day, but we need to get on this as soon as possible. We need to talk to your sister, but I wanted to see how she was holding up with the news."

John chewed on his lower lip, breath hanging in front of his face as he exhaled.

"Well enough, I suppose – it's hard to tell. There isn't a manual for this sort of thing, is there?"

"Unfortunately not," Hassard agreed. "It'll be Greg and I talking to her. Can you warn her, please? I don't want to surprise her by showing up unannounced, but she's got to speak to us."

John gave a dry laugh, tinged with bitterness.

"I doubt she'll want to talk to me," he pointed out.

"You're still her brother. You might want to be there when we meet with her. Someone should be. It'll be hard, I know, but it's only going to get worse once the trial starts up."

"Trial?" John asked. "That's getting ahead of things, isn't it? We need to find Mary first."

There was a pause on the other end of the line, and John felt something tighten in his chest, making his breathing swallower and quicker.

"John, where are you?" Hassard asked.

"Regent's Park. I needed coffee and some air."

"You haven't seen the news?"

"What news?" he demanded. There was a muffled conversation on the other end of the line – he heard Lestrade's voice in mix – before Hassard came back.

"We've just shut down all of Heathrow. Mary was spotted there, passing as airline personnel. It's on–"

"I have to go," John interjected, hanging up before Hassard could finish her sentence, abandoning his meagre breakfast on the bench as he took off running toward Baker Street.

The silence of the flat was a mixed blessing – it was easier to work without the unspoken questions emanating from John, without the palpable impotent frustration, but the lack of his presence was in itself distracting. No matter that the outing was short, no matter that Sherlock was back at Baker Street. Without John here, the house seemed huge and hollow, the doctor's temporary absence only compounded by Mrs. Hudson' permanent one.

In the back of his mind, Sherlock kept a running clock, counting down from twenty minutes. John would be punctual, because that was his way, and he'd be especially aware of the necessity now.

He could work for twenty minutes on his own, Sherlock told himself. It took some effort to refocus, which made him scowl and privately insist that there had to be a more efficient way of managing this. He was used to thinking of John on a regular basis; he'd simply have to get used to this new reality as well.

When he had time to indulge it, which he didn't right now. It wasn't just the clock ticking on John's return, but every moment that brought the doctor closer to coming home put Mary further and further out of their reach.

The buzz of his phone on the table made him snarl in the silence – Mycroft's name on the screen was one of only two right now that prompted him to answer. Sherlock gave himself the length of a short vibration to glare at his brother's name before answering.

"Mycroft," he said peremptorily, wondering what it would to get his brother to get to the point immediately so he could hang up.

"Well no," a female voice said on the other end of the line, apologetically friendly, making him stop cold. "But I'm glad it worked, because your brother's number was tricky to hack. I suppose you could run a trace, if you wanted to know where Mycroft is."

"Where are you?" Sherlock demanded.

"Haven't you seen the news?" Mary asked cheerily. "It's all over the telly."

He took the necessary bait, the colour and sound a sudden shock in the stillness of the flat. The BBC had overtaken whatever programme had been airing with a report of the shutdown at Heathrow. Sherlock thumbed up the volume loud enough to hear it without drowning out Mary's voice on the other end.

"Not a very good picture of me," she commented of the photograph in the upper right corner of the screen. "Of course they never are."

"Interesting time to call," Sherlock observed. "I'd thought you'd be rather busy with an entire airport shut down and the police searching it systematically for you."

"You'd think so," Mary agreed. "Then again, I'm not there. It's astonishing what people can be lead to think they saw, isn't it? Of course, it's easier when there's a bit of money jogging their memories. But you needn't worry about me; I'm having tea at an old friend's."

"What do you want?"

"What makes you think I want anything, Sherlock?"

He felt his nostrils flare at the use of his first name but kept his voice level, disinterested when he replied.

"Everyone has an agenda."

"True," Mary agreed. "You ought not to confuse mine with Sebastian Moran's, though."

"Difficult for a dead man to want much of anything," Sherlock observed.

"Whatever his agenda would have been had he been alive then," she conceded. "This is what I want, Sherlock: to give you just the right amount of answers to satisfy you – even though you will never admit to John that it's enough, because what would he think of you then? And please, don't bother with righteous indignation over what I've done to John and how you'll track me down for his sake. You could do that, but consider what you'd be missing if you did. All that precious time that can never be made up."

"What answers?" he asked, steeling himself to neutrality. Her assessment didn't matter – nor the fact that she was correct. Details were important; it was within those details that people gave themselves away. Mary would give far less than most, but there would still be something.

"Sebastian Moran was a useful tool. In some ways we had a very similar skill set, but why complicate the work with unnecessary emotion? Don't you agree? He became problematic. Unpredictable. It did wonders for his reputation – which has been immensely valuable, believe me – but it became difficult to keep him in line."

"You had him killed."

"There are times when, if you want something done right, you've got to do it yourself. The thing about getting your hands dirty is that they can always be washed clean. There were some circumstances that had to be controlled, of course, but it always works out in the end. Particularly for you."

"How so?" Sherlock asked.

"Had it been Moran you'd actually been looking for, there would be no conversation. A revenge-addled madman. Isn't that how your brother described him? An understatement, if I'm being completely honest with you – which of course I'm not, but in this case it's true."

Two small beeps intruded on the conversation; Sherlock pulled the phone away from his ear, smirking dryly when he saw his brother's number on the screen again. Easy enough to decline that call; Mycroft would want to give him erroneous information, assure him that Mary would be found, reassure himself that the disruption (and it would be massive; Sherlock could envision the ripples already spreading out across the globe) was worth it.

"And it's always nice to be right," Mary continued. "I'd worked it out ages ago, but it was interesting to listen to John explain it – there were a few details I'd got wrong. It was very creative of you, you know."

"What about Adair?" Sherlock asked.

"Business," Mary replied, and he could hear the shrug in her voice. "Nothing particularly interesting, certainly not to you."

"What happens now?"

"For whom? For you? For John? For Harry?"

"For Mary Morstan."

"What happened to Richard Brook?" she asked in reply. "Mary is a lot like him – she didn't exist until she was needed, and suddenly she'd always existed."

"You did that," Sherlock said, realization dawning like a cold light. "Richard Brook."

"Of course. It's not difficult. It's all just masks."

"And Sebastian Moran?"

"The best masks are often real people," Mary replied. "Less work to build the history and all that goes along with it. Bousquet doesn't know, in case you're wondering. What good is the myth if it's explained away? Moran's a good cover, lets me do my job."

"The job that died when Jim Moriarty did?" Sherlock snapped.

There was a pause on the other end of the line, then a smile – a genuine touch of laughter – in Mary's voice when she spoke.

"Mister Sherlock Holmes, have you not been listening to me?"

"Very carefully, in fact."

"Then perhaps not carefully enough. The reputation is important, particularly if the man behind it is known for his capriciousness and not for his tolerance or mercy. But a person is a tool, and when that tool breaks, it needs to be replaced. Moran became too difficult to control, and he had to go. So did our good friend Jim."

Everything fell away, the floor beneath his feet still solid but leaving him standing on nothing, the faint beeping of Mycroft trying to call again barely registering through the white haze of terrible realization. He felt suspended, not breathing, heart caught in the middle of a beat, the pieces falling into place to reveal a vastness he hadn't even considered. One in which even Mycroft, with his innumerable and hidden resources, seemed suddenly insignificant.

"And so, it seems, must I." Mary's voice collided with the shock, shattering it, yanking him back to reality. "You won't see me again, Sherlock – not any version of me. That's a promise."

The line went dead, and Mycroft's name appeared again, accompanied by a faint buzzing. Sherlock stared at his phone blankly, eyes fixed on his brother's name without really seeing it, replaying the conversation on a loop, searching it for the clues she must have meant to drop.

Have you not been listening to me? Then perhaps not carefully enough.

I'm having tea at an old friend's.

The door was thrown open with a bang, the sound of his shoes clattering down the stairs echoing in the empty common corridor. Mrs. Hudson's wasn't locked – she'd never bothered with it much if they were at home during the day, and neither he nor John had fallen out of the habit she'd left for them.

The sucking silence in her flat was indication enough – it was as empty as he'd expected to find it, as empty as Mary wanted it to be. Nothing had been disturbed. No windows left open. No hint of perfume on the air. Nothing taken or moved.

Except for the single empty teacup and saucer sitting in the middle of the coffee table. Still warm against the pads of his fingers when he pressed them on the base of the cup. A drop or two of dark liquid remained as mute evidence against the white porcelain.

Mrs. Hudson's best china. It had a sister sitting on the mantle where he'd abandoned it days ago; Sherlock hadn't missed how it had annoyed John, but hadn't understood why until now.

"Sherlock!" John's voice bounced off the walls, reverberating with the slam of the front door, and Sherlock was running into the corridor to catch John before the doctor went upstairs, fingers wrapping around shoulders, feeling the warmth and tension through the layers of fabric.

"Did you hear–"

"Did you see her?" Sherlock interjected, watching John's blue eyes narrow then widen, bright with confusion.

"What?"

"Did you see her? Mary, John! Did you see her when you came in?"

"What– Sherlock– how could I have? She's at Heathrow! I was just talking to Sergeant Hassard and she said–"

"It's not her. Mary, John, it's not her at Heathrow! She was here, she was just here!"

"What?"

"In Mrs. Hudson's. She left before I realized. Did you see her?"

A faint, stunned shake of John's head had Sherlock wrenching the front door open again, the desperate hope dying almost before it was born. Startled pedestrians gave him puzzled looks; he ignored them, scouring the street, watching for cars that were too still, or pulling away at precisely the right time.

There was nothing. Nothing out of the ordinary. Nothing to suggest she'd ever been there, save for the abandoned tea cup in Mrs. Hudson's silent flat.

Of course John hadn't seen her, and nor would Sherlock.

She had promised that.

"She was here, Sherlock? What– how do you know?" Sherlock slammed the door behind him, tilting his head back against the solid wood until John's cold hands on his face forced his gaze back down.

"She's gone."

"You said she was just here!"

"And now she's gone. She called me, John. It's not her at Heathrow. By the time I realized where she was, she was gone."

"Call Mycroft," John insisted, voice taking on that familiar firm anxiety he adopted when he needed to believe something would work. "There are cameras all over this area – he'll be able to find her on those and we can get the area cordoned off and it'll be just a matter of time–"

"No."

"No? No? What do you mean 'no', Sherlock? We have to find her! Are you suggesting we just stop now because–"

"I mean no, it's not a matter of time, John. She's gone."

"She was here," John hissed. "You said so! That means she's close by and we can find her, Sherlock! We need to find her! She knows where we are and now there's nothing stopping her from getting to us!"

"She won't," Sherlock replied, mildly – distantly – surprised by the evenness of his voice, by the detachment of his tone.

"What? What do you mean? Why not? We killed her boss, Sherlock! Okay, he killed himself really but is she going to be bothered by those tiny details? She was Moriarty's right hand man, like you said, she's going to want revenge for his death and–"

"No."

"Why do you keep saying no!" John yelled.

"We were wrong, John. About her. We were wrong about her."

"Wrong how?" John spat.

"We didn't kill her boss, and she doesn't care. Mary wasn't Jim's right hand man, John. He was hers."