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A River Without Banks

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"You name it, the world is aflame. We always have a mix of complicated interests. That's not unusual. What's unusual is there's this outbreak of violence and instability everywhere."--Gary Samore, former national-security aide in the Obama administration, to the New York Times, July 22, 2014

 

Life, to be sure, is nothing much to lose

But young men think it is, and we were young.

--A. E. Housman

 

 

“Not a peep,” the man with the scarred face said, leaning against the wall by the basement door.  “If he’s really back—“ He lowered his voice, even though there was no one else within earshot. “—then nobody around here’s heard about it.”

Sherlock nodded. It had been the same all night. Actually, it had been the same all week. If Moriarty had really returned from the dead, he had a peculiar way of declaring himself open for business: no one in Sherlock’s extensive network of criminal contacts had had any sign of him.

“All right,” he said. He held out a folded note, but the man shook his head.

“Didn’t tell you anything worth that. Didn’t tell you anything at all.” There was the sound of a flurry of punches from below and a muted roar: the small crowd sensing blood. “Ah, I’d best be getting back.” He turned to go and then hesitated, looking back at Sherlock in the dim light of the corridor. “You might look up that lot at the old Masonic temple, down by the river. I’ve heard tell some of his old associates are part of that.”

“The Scowrers,” Sherlock said. “I’ve checked. They seem as ignorant as everyone else.”

“You believe them?”

“They asked me to hide them in case it turned out to be true.”

The man gave a short bark of laughter. “Good enough. If I hear anything, I’ll ring.”

“Thank you,” Sherlock said. He watched as the man pulled the door shut behind him, then walked out into the cold alleyway behind the building, considering his options. These were dwindling rapidly, as he had essentially exhausted both his homeless network and his usual sources, and the night was wearing on toward morning. He decided to head for a part of town where he could get a cab for Baker Street. Maybe a walk in the frozen air would clear his head. He cinched his scarf and almost said “Let’s go,” before he caught himself: John was not here, John was not going to be here, not anymore.

Sherlock pushed down the sudden sharp stab of loss—every time,it still hurt, every time he remembered John had moved on—and strode purposefully toward the road. He had not seen John or spoken to him since their aborted farewell on the tarmac a week ago, and before that he had not seen him since the disastrous events of Christmas Day. It had been Mary who had come to see him in the holding cell, alone.

“He’s still angry, isn’t he,” Sherlock had said.

Mary had sighed. “He’s angry at life for not working out the way he wanted it to, which is stupid and childish. And he’s angry at me, but he can’t be angry at me now he’s decided to commit to this—to me, to us, to our child, our family—so, yes, he’s angry at you instead. He thinks he doesn’t want the drama anymore.”

Which was, frankly, unfair, Sherlock thought, pulling his coat more tightly around him as he strode through the frozen slush. It was enough to make one believe Mycroft was right about caring. There was a sudden gust of cold wind and he tucked his chin down into his scarf, curling his gloved fingers inside his pockets. He’d been out all night and was starting to think his toes might be permanently frostbitten. A few more streets, he thought tiredly, and then a warm cab home.

 

Sherlock longed to be curled up by the fire in his pajamas and dressing gown with a cup of tea, but he was too exhausted to fill the kettle and the thought of pulling off his clothes in the predawn chill of the flat was even worse. He left his coat on as he pinned his latest set of notes to the already crowded wall instead. He could not shake the feeling that the whole thing was an exercise in futility. He had been convinced for days now that the whole thing was most likely an elaborate hoax.

“Don’t say that,” Mycroft had almost snapped. “Don’t even think it. You’d be back on that plane in an instant.”

Sherlock stared at him, a suspicion too ridiculous to take full form hovering on the edges of his mind. “You didn’t…”

“Of course not.  And no one else would have reason; hardly anyone knew of the arrangement in any case. We’d hardly made a public announcement of it.”

Mary and John knew, thought Sherlock, but that way led to suspicions he really couldn’t let form. Mary had cut her old ties. He believed it. He had to, or there would be no way he could get on that plane when the time came.

“Our best chance is if the broadcast repeats. I’m watching for it this time; if they repeat the transmission, we’ll be able to pinpoint who’s sending it.”

And they had. A week to the day after the first broadcast, the same message had played again, forty-five seconds of Moriarty’s gleeful jeering interrupting every programme on every network, carefully timed to peak evening viewing for maximum impact. Sherlock had rung Mycroft immediately, only to be told curtly that he would be notified as soon as Mycroft had anything to relate. With nothing else to do, he’d bundled into his coat and headed out for yet another round of questions.

Sherlock checked his phone again—still nothing—and leaned his head briefly against the wall. It was impossible: if Moriarty was back, he had to be somewhere, someone must have seen him, but how was he back at all? Sherlock had seen him die. He had stood inches from Sherlock, looked into his eyes, and blown out the back of his head. How was he back? How?

Sherlock turned away from the flat’s silent reproaches of his failures—the wall of dead ends, John’s empty chair—and lay back on the sofa, wrapping his coat tightly around himself. He needed to think. This accumulation of negative data had to mean something; there had to be a pattern; he just had to find it. If only he weren’t so tired.

You love this, being Sherlock Holmes.

He had once. When had it all gone so wrong?

 

Sherlock had meant to spend the time puzzling out how Moriarty could have faked so spectacular a suicide as blowing out his own brains, but he hadn’t slept in days and he slipped into the dream as though falling into a deep, dark well. At first it was almost a good dream: he could hear John’s voice, calling to him, and John’s voice was not as it had been so often since Sherlock’s return--a little strained, too-tolerant, that sharp edge to it---but as it had been before: pleased, admiring, affectionate. He tried to go to him but John’s voice changed and he was angry, so angry, angrier at Sherlock than he had ever been and Sherlock knew why. He had failed. He had done the wrong thing, made the wrong decision, it had all gone to hell Mary and John and the baby, the baby, and then it was dark and he was alone. Utterly, terribly alone.  He couldn’t bear it. Sherlock turned frantically, searching, but he was alone in the dark and suddenly he knew what the dark hid: the cellar, the table, the men, the pipe—

Sherlock jerked awake, gasping, and then jerked away again in shock when he realized that Mycroft was directly over his face, hectoring away in his most sanctimonious and annoying voice.

“Sherlock Holmes, wake up. There are lives hanging in the balance whilst you lie here—including your own, as I should not have to remind you.”

“Go away,” Sherlock managed. He pushed himself upright. His brain felt thick and fuzzy, shreds of dark dream clinging to it like fog.

Mycroft sat back on the coffee table and looked at him. “Serbia?” he asked as though inquiring about a mutual and rather uninteresting acquaintance.

“No,” Sherlock said shortly. Coffee, he thought. He stalked to the kitchen with as much dignity as he could manage, set the coffee going, and went to wash. When he returned Mycroft handed him a full mug, sweetened exactly as he liked it, and carried on stirring his own cup.

Sherlock gulped half of it down in one go and immediately felt better. “What are you doing?”

“Adding milk.” Mycroft tasted, then added a bit more. “Obviously.”

“I don’t have tinned milk.”

“No, I’ve taken to keeping a few tins in the car. I have no intention of ever sniffing anything in your refrigerator again.”

Sherlock tried to remember the last time he had opened the refrigerator. He couldn’t. “Leave the rest here, I’ll have it in my tea later.”

Mycroft gave him a thin smile and carried his coffee to the lounge, settling into a desk chair with an air of conspicuous politeness that annoyed Sherlock more than if he had sat in John’s.  Sherlock took his own coffee to the window and looked out, still feeling slightly heavy-headed. The day was January-grey and dreary, passers-by below huddled into coats as they scurried through the cold. Sherlock glanced at his watch: nearly noon. He had slept longer than he realized. He downed the rest of his coffee, refilled his cup, and settled into his own chair. “Did you locate the source of the transmission?”

“Yes. We’ve arrested the person who broadcast it.”

“Not Moriarty.” Mycroft would have said at once if it had been.

“No. The person who broadcast the transmission refused to identify herself, so we entered her fingerprints into the database and immediately found a match. According to her fingerprints, she is a woman named Victoria Trevor. Does the name mean anything to you?”

“Victoria Trevor,” Sherlock repeated in surprise. “Yes, of course. I knew her at university. She was finishing her PhD in physics when I was reading chemistry.” Sherlock had not thought of Trevor in years. He remembered her as silent and thin, fair hair cut in a chin-length bob she had probably worn since childhood, always dressed in twin sets or neatly pressed blouses and cardigans. Pearls and matching earrings. She had been entirely focused on her work, which was the only reason Sherlock knew her at all: a gradual acquaintance born of always being the last two people in the research building. “What would she be doing with a video of Moriarty?”

“An excellent question, and one which she has so far refused to answer. In fact she will say nothing except that she wishes to speak to you. The problem, however, is that she is not Victoria Trevor.”

Sherlock frowned. “You just said that she was.”

“I said that her fingerprints identified her as Victoria Trevor. She isn’t. For one thing, Victoria Trevor is currently working at a private research facility near Lincoln. And by currently I literally mean currently—we’ve had agents on her since last night.”

“What’s the other thing?”

“That,” Mycroft said, setting down his coffee cup and rising to his feet, “is something you are going to have to see for yourself. Ready?”

 

Sherlock followed Mycroft down the corridor of the nearly-deserted holding area, footsteps loud against the concrete floor. Mycroft stopped in front of the only occupied cell and said politely, “Good afternoon.”

The woman in the cell did not answer him. She stepped closer to the bars, tipping her head a little to study Sherlock, and Sherlock saw her clearly in the fluorescent light. She was as pale and angular as he remembered, sharp eyes even lighter than his own, pearl earrings and sharp-edged haircut the same—for all he knew she was even wearing the same silk blouse and cardigan. But her hair was entirely white, and her face deeply lined. The woman in the cell was at least twenty years older than Sherlock.

Sherlock blinked several times, trying to process, knowing the truth already even as the larger part of his mind refused to accept it. “Mr. Holmes,” the woman said. “You’re looking very well. I don’t know that I would have recognized you.”

“It’s been a long time,” he said neutrally.

“Longer for me than for you, I think, if we’re counting from Oxford.”

“Mmm.”

She smiled very slightly, pushing a strand of hair behind her ear with one finger as she always had, and it was that more than anything that made him believe. “You should cut a fringe,” he said, almost a reflex.

“But then I would have to remember to trim it.”

Sherlock grinned. He couldn’t help it. He grinned because Trevor had once been the closest thing he had to a friend, and seeing the warmth in her eyes made him realize that he could badly use a friend. He grinned because this was amazing, the most fascinating and interesting thing that had happened in ages, and he couldn’t wait to hear more. And, of course, he grinned because this was going to blow Mycroft’s narrow little mind entirely. He turned to Mycroft and said, “It’s her,” and had the satisfaction of seeing Mycroft’s mouth drop open in shock.

“I really need to speak with you,” Trevor said. “I’d invite you in, but I’m afraid my current accommodations lack sufficient seating for guests.”

“Mycroft, find us a conference room or something, will you? Trevor and I need to talk.”

“In privacy,” she added.

“He’ll just listen in.”

Mycroft finally seemed to realize he was gaping. “If you will excuse us a moment,” he said to Trevor and dragged Sherlock off down the hall. “What are you,” he hissed. “you can’t—how can you possibly be taking this seriously?”

Sherlock had never seen his brother too flustered to complete a sentence. He looked at Mycroft with a surge of unfamiliar compassion. “Because I’m a scientist,” he said gently. “You’re a…” He hunted for a flattering term. “…statesman. You decide how the world should be and you make it that way. Scientists know that the universe is bigger than we can possibly imagine, and it can always surprise us.”

Mycroft stared at him unhappily. “You really believe this is Victoria Trevor,” he said. “Even though all records say that Victoria Trevor was born in 1974. Even though a woman all her colleagues seem to believe is Victoria Trevor is sitting in a lab in Lincolnshire right now.”

“Yes,” Sherlock said simply.

Mycroft rubbed at the back of his neck, looking unhappy. “All right. I’ll make arrangements to have her released—it’s hardly likely she poses much of a threat in herself. And you needn’t worry about my eavesdropping; I haven’t the leisure. I don’t think you realize, Sherlock, that there is enormous pressure on me to resolve not only this issue with the Moriarty transmissions but with Mirzayev. I’ll do what I can, but we’re running out of time.”

 

They ended up at a safe house of some sort, completely unremarkable from the outside, decorated in a beige blandness that put Sherlock’s teeth on edge. Two of Mycroft’s exquisitely polite minions accompanied them, apparently to make tea or fend off any threats, as the occasion required. Sherlock felt they might as well take advantage of the tea and had a plate of biscuits sent into the study as well.

“All right,” Trevor said, setting down her teacup. “Do you remember what I was working on at university?”

“Temporal physics,” Sherlock said. He had a faint but clear memory of a damp spring night, drinking coffee, Trevor’s swift fingers sketching equations on a page as she talked. “You had developed a theoretical model for treating time not as a linear constant but as a variable in a system.”

“Yes. I’ve advanced beyond the theoretical now, obviously.” That faint smile, a little wry this time. “Well, not now. It took me nearly fifty years to get to this point. On the strength of my dissertation I was offered a position at the government facility at Baskerville. After about ten years I had developed a prototype, and we started testing in mice. That’s when the trouble started. “

“You tested time travel on mice?”

“Of course I did. The IRB was hardly going to let me use human subjects. And it wasn’t time travel as you’re thinking of, not like this—I just told you I only perfected the actual mechanics for this in the past few years. What we did then I called wrinkling, after the book, A Wrinkle in Time. Do you know it? It was my absolute favorite as a child.” She looked at Sherlock’s blank face. “No. You’re more the Harriet the Spy type anyway, I suppose.”

“Trevor,” Sherlock said in exasperation, “you are babbling. You never used to babble.”

“Well, I’ve got old, Holmes. Never mind. In a wrinkle, one doesn’t travel physically to a different point in the time stream the way I have. If I had wrinkled, I wouldn’t be here talking to you while my forty-year-old counterpart works in Lincolnshire. I would be my forty-year-old counterpart in Lincolnshire. The calculations involved, the energy required—it’s all far less complex if you go only into your own past.”

“But would you know that you had done it?”

“No, you wouldn’t. You wouldn’t carry the memories of what had happened to you later in the time stream, although you might retain faint impressions at a subconscious level.”

“So you sent mice back in their own pasts.”

“Yes. And it worked, too, exactly as predicted. But there were two unanticipated problems. The first was that there were adverse effects—the mice did not react well to being moved about in time. They stopped eating, became aggressive, self-mutilating and so on. We tracked them out several months—some of them years—and the interesting thing was that not only the subject mice were affected but also their close contacts—cagemates, for example. I was sure this was a problem only in lower intelligence subjects and that if we expanded trials to higher order primates it wouldn’t occur, but the IRB didn’t agree. As it turned out they were right, though I refused to believe it at the time. There seemed to be a few factors involved. For one thing, the animals who were already unstable were much more likely to be affected. When we replicated the trials in chimps, those who were already moody or aggressive were more likely to suffer from the temporal displacement effect. Also, it turned out that there was an inherent integrity in the original time stream, so the greater the deviation, the greater the effect on both the primary and secondary subjects.”

“So if, say, a murderer went back—if he wrinkled,” Sherlock said, “and he killed someone else, the negative effect would be felt not only by him but by the now-surviving victim.”

“Exactly, although that’s hardly the example I would have used. Really, Holmes, where do you come up with such things? It didn’t matter in any case as the IRB refused to clear further studies and so Baskerville pulled the plug on the project. They would have been delighted for me to stay on and work on something else, of course, but I couldn’t bear to give it up. By incredible good luck—or so I thought at the time—I was offered a generous grant at a private facility to continue my project. And the funding for that…”

“Moriarty,” Sherlock breathed.  Of course Moriarty would have seen the potential in Trevor’s work, and he certainly wouldn’t have been bothered by the risks.

“Yes.” Trevor looked away for a moment, clearly thinking, then tucked her hair back again. “Now it grows complicated. Let me tell you what is known first, and then what I believe to be true. About fifteen years ago, for me—so about fifteen years in the future for you—an event horizon appeared in our solar system. To make a very long story extremely short, there had been an increase in entropy starting at the point of my initial experiments and progressing exponentially until it created a black hole. The process might have taken longer, but there was a sharp jump—an increase in the increase--about three and a half years prior to now. It was due to my work, Holmes. It turned out that altering time in a reaction produced an exponential increase in entropy, like this.“ She pulled a pad of paper over and wrote out a series of equations, tapping her pencil on the relevant portion.

“But you could have corrected for that, couldn’t you? Stabilized it?”

“Perhaps. With the models I had in place, I would have had an ideal situation for testing it. Not likely I’ve enough lifetime for that now, though. You see, it wasn’t just the actual physical entropy that increased. What you might call the layman’s entropy increased also, starting from right about now. The amount of disorder and chaos reaches a sort of tipping point, and it seems that your mission is the catalyst. That’s why I had to stop you going. What you do there—it sets in place a sort of chain reaction, and things just…fall apart.” She looked at him sadly. “It hardly matters that the world is about to be swallowed by a black hole, because there’s very little left worth saving.”

Sherlock could only blink at her, stunned. In his wildest imaginings he could never have considered this. “But just stopping me now—that won’t reverse the singularity. What happened three and a half years ago?”

“I don’t know for certain,” Trevor said quietly. “But I think you can guess.”

Sherlock stared. No. This was not—she could not possibly be suggesting that. “Trevor. Are you saying that Moriarty altered time by going into his own past and killing himself?”

“Yes,” she said. “That’s exactly what I think. I think he used my prototype without my consent—or at least I quite hope without my consent—to change something in his own life, but in the process set in motion a devastating chain of events and ripped a hole in the space-time continuum.” She shrugged a bit self-consciously. “In lay terms. Oh, and I don’t think he planned to kill himself. The man was insane to begin with, that much was clear even to me. I think the temporal displacement effect undid him completely.”

“But wouldn’t we be aware of it? You said the primary time stream had its own integrity. If we’ve been affected—if I’ve been affected—by this, wouldn’t I be suffering the effects too?”

“Aren’t you?” Trevor asked, her pale eyes unblinking on his. “How have you been sleeping lately, Holmes?”

Sherlock opened his mouth, stopped, and slowly shut it again.

“How long have you been feeling it? That things have somehow gone wrong?”

“I don’t know,” he admitted, looking away. “A long time.”  Since John had moved on. Since Sherlock had come back. Since he died.  

“If we can fix it,” Trevor said, “we can restore the primary time stream. According to my calculations that would reverse the singularity.”

“But you don’t even know what the primary time stream is supposed to be! What if Moriarty wins? What if I’m the one who dies?”

“You might. I don’t know.”

Sherlock sat back and frowned at her. “I know I’m supposed to be a raging egomaniac, Trevor, but even I never fancied that I might be called upon to save the universe through my noble death.”

“Not the whole universe; the black hole would probably—“ She caught his look and her mouth twitched slightly. “Ah. Right.”

Sherlock exhaled a long breath. “You want me to go back. To fix this.”

“That’s why I came back, yes.” She took a sip of her cold tea and grimaced, pushing the cup away.

“Would you mind terribly if I took a bit of time to think this over? You must be starving; I’m sure Mycroft’s minions can get whatever you like to eat.”

“Actually, what I’d really like is to lie down for a bit. Spending the night being arrested and interrogated is a bit wearying at my age.”

Sherlock smiled at her. “I’m sure that can be arranged.”

 

The safe house had a tiny garden, barely big enough for a pair of chairs, with high walls on all sides. Sherlock stood out on the frozen grass and smoked two cigarettes down to ash, staring blankly up at the grey sky. He was almost surprised to find it still daylight; the day already felt as though it had gone forever.

What he really wanted was to talk to John. You keep me right, Sherlock had said, and it was true; every decision he had made without John had turned out to be rubbish. If he did what Trevor wanted he might never even meet John. The thought made him feel hollow and achy. It was worse somehow, to think that he might never know John than to know that John had left him. But what if that was the right thing to do? This was why he needed John: because he didn’t know. John was his moral compass, his normal people guidebook, his map to the right path.

Sherlock pulled out a third cigarette, then abruptly shoved it back in his pocket and pulled out his phone, checking the time. Not even five, Sunday afternoon, so not at work; maybe John could meet him for a pint or an early dinner. He hit the speed dial quickly before he could change his mind.

The phone rang four times and Sherlock was just wondering whether or not to leave a voice mail when John picked up. “Sherlock! What’s happened, do you have news?”

“Yes, but it isn’t—“

“Wait, hold on a minute, I can’t hear a thing in here.” Sherlock could hear a tumult of voices; perhaps already at a pub? no, the acoustics were wrong, John was moving, now there was running water and women’s voices. A kitchen. He was in a house. A door slammed and John’s voice said breathlessly, “Jesus, it’s cold out here. Did you get him?”

“It wasn’t Moriarty. It was a hoax.”

“Shit.”

“John, the person who did it—it’s very complicated, but there’s a chance that I can fix things. A lot of things. I was hoping I could see you tonight, or in an hour or so if you’re free—“

“Christ, Sherlock, I can’t. We’re at Mark and Julia’s, you remember from the wedding? They’re having a bit of a baby shower for us. Maybe tomorrow—“

Sherlock felt the cold disappointment settle into his stomach, not least because it did not escape his notice that John did not sound particularly disappointed. John, after all, didn’t want the drama.

“—no, wait, I forgot, Mike’s coming over to help us set up the cot, but—“

“It’s all right,” Sherlock cut in coolly. “I’ll text you later.” He wouldn’t.

“Sherlock—“ But then there was the sound of a door slamming again and a voice Sherlock didn’t recognize said, “There you are! What are you doing out here? Come on, John, everyone’s waiting for you.”

“Sorry, Sherlock, I’ve got to go. Listen, I’ll ring you tonight, okay?”

Sherlock disconnected without answering. He smoked the third cigarette. Then, feeling slightly queasy, he sat down in the little chair and pulled his coat tightly around himself, prepared to get advice from John in the only way left to him.

Sherlock found John in his Mind Palace in the room he had set up for him, a room that looked just as the lounge at 221B had when John had been living there. The fire was crackling, and John looked over his newspaper at Sherlock as Sherlock perched on the edge of his own chair. “So.”

“What if I was supposed to lose?” Sherlock asked bluntly. “What if I go back, and he wins, and I die?”

“Well, we’re all going to die,” Mind Palace John pointed out. “You’re going to die if you get on that plane. But it rather sounds as though you’ll be saving the rest of us, and isn’t that what you wanted all along?”

“No,” Sherlock said honestly. “I wanted to beat Moriarty.”

Mind Palace John shrugged “You did. You were a great man. Now you have the chance to be a good one.”

“But what if I’m not?’

“You could be.”

Sherlock sighed, wrapping his arms around his knees, staring into the fire.

 “I couldn’t go with you in any case,” Mind Palace John said kindly, looking at him over the newspaper again. “You know that, don’t you? Even if I were really here, you have to do this on your own.”

“I’m rubbish on my own,” Sherlock said. “You know that. You’ve always known that.”

Mind Palace John rattled his newspaper as he turned the page. “Look at it this way. What have you got to lose? Beats getting on that plane.”

And that, Sherlock reflected, was true enough.

 

Trevor was back in the study when Sherlock returned, looking more refreshed and eating a sandwich whilst she flipped through the newspaper. “What do I need to do?” Sherlock asked.

Trevor looked up, a strand of silver hair falling across her face. She pushed it back with one finger and gave him her faint, barely-there smile. “We’re going to need your brother.”

 

“I have my people in position,” Mycroft said. “Are you certain that—you—have left the lab for the night?” Mycroft looked as though the very act of constructing this sentence had curdled the saliva in his mouth.

“Yes. I’m a bit of a workaholic, but I usually take Sunday evenings to have a glass of wine and catch up on my reading. Journals,” Trevor added, as though worried they would consider reading trivial.

“Very well.” Mycroft nodded to Anthea, who disappeared, tapping silently on her mobile. “They should be here within a few hours.”

Trevor frowned. “Here? I don’t think it’s going to fit. The apparatus is constructed from a converted MRI scanner; it’s quite large.”

“The cellar is rather roomier than one might expect,” Mycroft said. “I’m not worried about space. I’m worried about what you are planning to do to my brother with it. Explain to me exactly why Sherlock needs to go back to the point at which he was a university student, please.”

“I need to convince Trevor to give up her line of research,” Sherlock said patiently. “I told you before. We don’t know what Moriarty did differently or what he altered, so there’s no way to prevent him from acting directly without possibly making things even worse. But if Trevor never builds the apparatus in the first place, then he can’t use it, do you see?”

“Why can’t you do it? Wouldn’t that be much simpler?” Mycroft asked Trevor.

“I’ve tried. God, how I’ve tried. Apparently I can be very stubborn.”

Her eyes crinkled slightly at Mycroft—almost warmly-- and Sherlock cocked his head, curious, but was distracted when Mycroft said crossly, “But why Sherlock? Surely your thesis advisor, or one of your professors—“

“My thesis advisor was an idiot,” Trevor said dismissively. “I’d be far more likely to listen to Holmes.”

“Well, I can see why you two got on,” Mycroft said dryly. “But I didn’t mean this…wrinkling thing. Why didn’t you just go back entirely, the way you have to us? Surely if your, ah future self appeared…”

That, actually, was an excellent point. Sherlock was annoyed he hadn’t thought of it himself. He raised his eyebrows at Trevor, who sighed.

“I can’t get back that far. The amount of entropy produced in a temporal reaction is exponentially increased with the amount of time displaced, and exponentially again greater for a physical displacement than for a wrinkle. This—coming to you—it’s our last chance. If I had tried to go back any further from my point in time, it would have pushed us past the threshold of the event horizon. I didn’t even do any trials before I used this on myself to avoid bringing us closer.”

“I haven’t the faintest idea what you just said,” Mycroft said blankly.

Understanding something Mycroft didn’t was never going to get old, Sherlock thought happily. “Because if she had the universe would have imploded,” he said bluntly. “No, shut up, Trevor, you’ve got to use small words with him. And anyway it’s a moot point now, we haven’t the equipment and it won’t exist for another thirty years.”

“But then—you’re stuck here,” Mycroft said, looking surprised.

Trevor shrugged. “Either this works, and it doesn’t matter because we restore the integrity of the time stream and I’m back wherever I’m supposed to be, or it doesn’t, in which case I hope to die of natural causes before I reach the point I traveled from in any case.”

“I’ve got a spare bedroom,” Sherlock said. “How do you feel about solving crimes?”

 

Mycroft’s people arrived in a panel van a few hours later, directed by Anthea as they backed into the attached garage.

“I really don’t understand how we’re going to get this into the cellar,” Trevor said, looking around. “How does one get to the cellar, anyway?”

“Like this,” Mycroft said, and punched a code into the automatic door opener. The entire garage jolted and began to descend. A few minutes later, they ground to a halt and Mycroft punched in a second code, and the garage door slowly lifted to show a vast concrete space.

“You have an underground bunker beneath a safe house in the suburbs?” Sherlock asked.

Mycroft shrugged. “Among other places. And it has an extremely powerful generator—I imagine Dr. Trevor’s machine uses a great deal of power, and we don’t want to black out the whole neighborhood.”

Sherlock watched as Trevor went to direct the unloading and reassembly of the machine, which was unnervingly large. He felt a flash of claustrophobic anxiety. He would go into that thing and then—what? He wished suddenly he had had a chance to see Mrs. Hudson again, and Lestrade, and Molly. He hadn’t really thought about it when he’d died the first time, how it must have been for them, but now that he was on the other side of the equation he could not help but feel a stab of  regret. Well, he would always have Mycroft, he thought, watching Mycroft fussily overseeing two men carrying in a sofa, on which Mycroft would presumably rest his fat arse whilst Sherlock took all the risks, as usual. He tried to pretend this thought was not actually comforting.

“Holmes?” Trevor called.

“Ready,” he said, and pushed away from the wall to join her.