### Prologue

Time travel was possible after all.

The problem was eventually cracked in the early ’20s by a team of graduate students at UC Berkeley. They knew they were on the right track when they picked up a radio message in the lab, a message that they would send five months later.

Once the formal announcement was made, the media spoke of nothing else. Every newspaper was emblazoned with MAN CONQUERS TIME, every site and stream delivered round-the-clock updates covering the global orgy of speculation. Though the theory in broad terms was widely published, the implementation details remained a closely guarded secret. Scientists were interviewed who by turns hailed the breakthrough as the single most critical event in our history, or espoused their own theory of how this would lead inexorably to humanity’s destruction. Religious leaders universally decried it as a sin against God, while pundits held forth about the thorny problem of its legislation.

Yet week after week passed without humanity winking out of existence. There were no horsemen and no trumpets. The riots were fewer and farther apart; people returned to work; the pundits shifted their attention to a breaking presidential sex scandal. For most of the world, life eased back into normality.

And far beyond the hastily erected barbed wire fences, past the 24-hour armed guard, deep underground in a utility-plant–cum–Berkeley-lab, the original research team—at the gentle request of their newly appointed military counterparts—quietly stepped up their schedule.

### 21 September 2022

“Hey prof, you know time stuff, right? Quick question.”

Professor Abel frowned slightly and closed his eyes, pressed his fingertips against his temples. In the wake of the announcement last month, he’d become a bit of a minor celebrity. The most immediate effect of this was that he’d spent much of the past three weeks trying to explain the basics of temporal mechanics to inquisitive parties, with varying degrees of success. His enthusiasm for the whole thing was wearing dangerously thin. “Let’s hear it.”

The student hesitated. “You know the grandfather paradox? Like, if I go back in time and kill my own grandfather before my father is born. What happens if I really do that?”

Abel nodded. He’d fielded this one a lot. “The short answer is that you can’t.”

“You mean because I couldn’t travel back that far into the past? I heard there’s some kind of problem doing that,” replied the kid. Nick, that was his name. A decent student. Not one of his best. “Even if you could, it wouldn’t matter. Keep in mind that nobody’s actually gone and tested this yet; this part is all still theory. But it’s a very well-grounded theory.”

The kid was undeterred. “Yeah, I read that, but none of the articles talk about the big problem,” replied the kid. Nick, that was his name. A decent student. Not one of his best. “What if I did manage to go back and, like, find my own grandfather, and then I point a gun at him and pull the trigger. I mean, what happens? Do I disappear, or…”

Abel watched the last few stragglers from his class as they filed out. One girl dropped her phone and bent over to pick it up, affording him a criminal display of cleavage. His mind began to wander; he wished he weren’t on the wrong side of forty.

Presently he became aware that Nick was waiting for a response and he tried to refocus. “You couldn’t do it. It’s impossible.” Abel paused, collecting his thoughts. “But it’s not as though there’s any one step involved that you wouldn’t be able to carry out—well, nothing a priori. Given the motivation and resources, you could make it back to your grandfather’s time. The rest of it would be straightforward, ethical issues notwithstanding.

“But time loops are every bit as binding and immutable as gravitational attraction.

“As a whole, it’s impossible to carry out because you’re here. You already didn’t shoot him, and therefore there’s no sequence of future events that could result in his premature death. Once you grok the physics, the paradoxes melt away, and the question itself becomes a non sequitur. You’d literally have a better chance of walking outside and jumping into orbit.”

Nick started to object, but Abel barrelled on. “I know, I know, you could get it in your head to try anyway, and that’s where things become interesting,” he said, warming up to the explanation. “The universe would actually seem like it were deliberately conspiring against you at every turn. But no, you wouldn’t just disappear. Reality is far more creative than that. Our current understanding is that the obstacles you’re most likely to encounter are those events that were most probable to begin with.

“Without getting into the weeds too much, it basically gets into quantum many-worlds stuff. There will always be some versions of reality where for whatever reason, you don’t succeed in killing your grandfather, and it turns out you’re guaranteed to find yourself in one of those realities.

“For instance, the building with your time inverter might lose power, or you might have written down the wrong address for your grandfather. Maybe you make it all the way there but the gun jams, or maybe you get hit by a car when you walk out the door that morning. Nothing overtly sinister or inexplicable. In fact, since normal-seeming realities are vastly favored over less likely realities, you most likely simply wouldn’t feel like doing any of it in the first place, or someone would talk you out of it, or you’d wind up with a date that night, something prosaic like that. Really, the only guarantee you’d have is that it wouldn’t seem suspicious on its own. Of course, this is still all theoretical, but for now, this is the only plausible theory we’ve got.”

The boy seemed unhappy with this answer. “I guess I got it. But I thought of something else, too. What if the fact that I’m here now doesn’t prove anything after all? Because what if I go back and shoot him, and instead of changing things here and giving you paradoxes and stuff, it makes, like, a parallel universe where I’m never born?”

This was another concept that Abel had run into a fair amount in recent days, so he was prepared. The question was essentially gibberish predicated on a gross misunderstanding of quantum mechanics, along with maybe watching Back to the Future one too many times. But you don’t become a professor without learning how to give good answers to bad questions. “Nice thought, but the problem there is that any internally consistent set of axioms we’ve come up with that can incorporate time-like loops ultimately necessitates a single-universe model, or the math doesn’t work out. Even if there are some sort of ‘parallel realities,’ or a multiverse, or whatever you choose to call it, it won’t make a difference. We’re effectively isolated—at least, where time travel is involved. We’re stuck with our one timeline.”

Nick spent a moment digesting this, then said, “Guess it’s a good thing we can reuse it, huh?” Still, Nick seemed unhappy with the answer. He was starting to object, but someone called over to him, so he thanked the professor and excused himself. As Abel finished packing up his things, he resolved to write a primer on this stuff to share with anyone else who buttonholed him. The core theory and its possibilities were endlessly fascinating, but answering the same half-dozen questions over and over was not.

“Dr. Abel?”

He looked up from his briefcase to find the room empty but for a man he didn’t recognize, standing by the doorway. The man was maybe in his late forties. He was slightly soft around the middle but stood with a posture and bearing that screamed military. He wore an understated dark suit and carried nothing.

“Yes, I am. What can I do for you?”

“I’m not sure. Perhaps nothing, but perhaps a great deal,” said the man, stepping closer and offering his hand. Abel shook it. The man had a confident, efficient, single-pump shake. Military-esque. “I’ve spent several days meeting with scholars in your field. They all tell me that you’re the best.”

Abel more or less agreed, but adopted an appropriate level of modesty. “I suppose that’s fair, but honestly a lot of that is luck. I sunk a lot of time over the past decade into following the theoretical work, back when everybody thought the whole thing was a pipe dream. That gave me a bit of a head start on everyone who’s been playing catch-up since the announcement.”

“As far as I can tell, that’s pretty much everyone but you,” the man said.

“Well—yeah, pretty much. Except for J.D. and his team at Berkeley, of course. It was all I could do to keep up with what they were publishing. It’s a smart group of kids they’ve got down there, it truly is.” Abel looked pointedly at his watch. Between classes and a flurry of speaking engagements, he had plenty on his plate already without getting entangled in some governmental affair. “Come to think of it, if you’re chasing down a consult for something, why not go straight to the source? I know they’re under some pretty stringent security now, but you strike me as someone with connections. And if not, I could maybe shoot him an email and put in a good word for you.”

The man raised an eyebrow but remained silent for several moments. He seemed to be considering something. After a glance back toward the empty doorway, he spoke, quietly. “Doctor, nobody’s seen J.D. or his team in over six days.”

“What do you mean? Last I heard, nobody’s seen J.D. or his team for about a month now, since right after they went public. I think they’re still locked up in that god-awful army complex outside Berkeley. ‘For their own protection,’ that’s the party line. It was all over the news, not sure how you missed it.”

“Air Force.”

“Pardon?”

The man sighed, took a phone out of his breast pocket. “It’s a U.S. Air Force complex, not Army.” He traced a couple of small gestures on the phone and held it up for Abel to see. The screen was displaying an ident indicating that Abel was standing in front of one Colonel Jack Shaffer, USAF Liaison. He knew that Shaffer’s phone was locally broadcasting authcodes, that his own phone would notice this and automatically query a central government server for verification. He could check his phone now and instantly see whether this man was truly Colonel Shaffer, but doing so would be a breach of etiquette. Besides, under the circumstances, he found little reason to doubt it.

Shaffer tucked his phone away and continued. “And it really was for their protection. You remember how crazy it was those first few days? After the demonstration vid got leaked on the Tube and everyone saw it was the real deal? People literally thought J.D. was going to somehow consign humanity to oblivion, or flat out incite the wrath of God. A lot of people. The NSA logged more credible death threats in one week for J.D. alone than they had on record for anyone else in the country over the past ten years. If we hadn’t moved to secure them when we did, I assure you that things would have ended suddenly and tragically.”

Abel was taken aback. He’d known the situation had been tense for a while there. Daily protests-turned-riots, plenty of political and religious leaders calling for J.D.’s imprisonment while the issues were discussed. A few of the fringe elements openly proposed assassination, but Abel had only laughed at the time. He’d written it all off as groupthink and reactionary posturing in a brave new world. More to the point, he’d corresponded with J.D. a number of times over the years, and knew the guy to be pleasant and mild mannered. The notion of anyone seriously wanting to do him harm was difficult to wrap his head around.

Of course, this could be a load of BS, but so far Shaffer had asked for nothing, and Abel was inclined to give him the benefit of the doubt. “Say I take your word for it. If you have that kind of information on him, you must know what they were up to these past few weeks, right? My imagination’s been running wild.”

“I’ve told you what I can,” replied Shaffer. “Hell, I’ve told you more than I should have already. SOP would’ve been to make you sign an NDA before giving you the time of day. But your background check came back spotless, and in any case, I’m operating with some fairly wide latitude here due to the time-sensitive nature of the situation.”

“In other words, you don’t know.” Abel tried not to sound disappointed.

“I’m saying that if I did, I couldn’t tell you.” Shaffer shrugged. “Though as it turns out, you’re right. The tech stuff is someone else’s department. My job has more to do with greasing the wheels between the USAF, Homeland Security, and a few other entities, making sure things run smoothly, silently, and securely.” He gestured expansively. “Alas, things have not gone as smoothly as we would like. Look, I’ll level with you, Professor. Bringing you on board was not Plan A. That said, we’re way, way beyond Plan A at this point, and it’s just possible that your cooperation will improve our chances of resolving this mess, so I hope you will agree to provide it.”

Abel wondered at exactly how desperate the man was. Shaffer’s expression remained stoic, but his words struck Abel as a genuine plea, and it took all of two seconds to make up his mind to help if he could. “Okay. You said J.D.’s team went missing a week—”

“Hey, prof!” Nick had reappeared in the hallway. “Just wanted to ask if it would be cool if I turned in my project proposal two days late. I’ve got a camping trip scheduled since like forever. White Mountains, it’s gonna be awesome.”

“It’ll be a ten point deduction. I went over that on the first day. Check your syllabus.”

“Yeah, fine. Thanks,” he said, and drifted off down the hall.

Shaffer seemed to have second thoughts about their venue. “That’s enough talk here. If you want to help us—if you want to help J.D.—we should leave immediately.” He cut off Abel’s protests. “We can have anything you need from your apartment overnighted, and I’ve already spoken to the dean about a sub for your classes. You’ll have to decide now, though.”

Abel looked at the stack of ungraded exams on his desk. He thought about watching J.D. on the Tube a month ago, all shyness and stammers at the press conference. He thought about time travel.

Really, it was no decision at all.

### 47 days earlier

“Hey guys, I don’t—guys! Over here, quick!”

Mason reluctantly pried his eyes away from his computer screen. Ada undid a wrist strap and stood up from the soldering desk. They both made their way over to J.D.’s workstation. He was fairly vibrating with excitement.

“You know how we’ve been trying to find a way to preserve fidelity in the uplink chipset?”

Mason yawned and rubbed his eyes. They’d been in the lab since yesterday afternoon, and the pale dawn light beginning to intrude through the blinds was an unwelcome sight. “You mean we were trying. Dude, we’ve been over this. There’s no way to clean up the signal degradation. It’s a dead end.”

J.D.’s normally sober expression was replaced by a goofy grin. “You mean it was a dead end. We’ve got another chunk of the transmission, and this one had a complete algorithm for boosting signal cohesion by a lot. We’re talking like three or four orders of magnitude, easy.”

This got Mason’s attention, and he stared dumbly at J.D. They’d spent weeks trying to coax a little more efficiency out of the chipset, and now J.D. was talking about an unconscionable thousand-fold improvement. If it were true, it would make all of their hard problems easy, and their easy problems trivial.

He shook his head. “Three or four… you’re shitting me, right? You’ve gotta be shitting me.” J.D. cackled with delight and pointed to the screen. Mason leaned closer and saw a comment block by J.D.’s finger, a small island of text nestled among reams of code:

    // REALLY IS 3-4 ORDERS OF MAGNITUDE. NOt SHITTING YOU    //      -future mason

Mason couldn’t help laughing too. The first time they’d read one of these prescient messages from Future Them, they’d been shocked and humbled, and sat for a long time in a silence pregnant with metaphysical implication. But by this point they’d stumbled onto a half dozen more, and it had become good clean fun. Besides, seeing as mucking around with time would probably end up transforming every aspect of human existence sooner or later, Mason found it comforting to know he’d still be taking pleasure in the little things a few months down the road.

Meanwhile, Ada was completely absorbed. Her dark, serious eyes were scanning through the program, a perplexed look building on her delicate features. “J.D., hold up. Have you actually tried running this yet? Because this is completely impossible. We tried everything. It’d have to be some radically different approach, and—well, nothing here looks new. All I see is a bunch of Mason’s garbage code.”

“Aww, you’re just jealous that I’m the one who figures it out,” Mason said cheerfully, giving her a playful punch in the arm. “Garbage code my ass. Twenty bucks says this thing runs flawlessly out of the box.”

J.D. paged through the code and frowned. “Wow. Garbage is right. This actually almost looks intentionally obfuscated. It’d take forever to work through.” He shrugged. “But I know a faster way to find out.”

They’d picked up the transmission some months back, but soon discovered that because of some unexplained glitch—they weren’t even sure whether it was on the sending or receiving side—large swaths of data had been corrupted. Fortunately, a few sections here and there seemed to be intact; it was enough, just barely, to determine from whom and when it had been sent.

As for the corrupt data, they’d found most of it padded with enough redundancy to be theoretically recoverable; in practice, this required a large and unpredictable number of CPU cycles. As a result, the summer had consisted of long stretches spent beating their heads against some intractable problem, punctuated by intense flurries of activity whenever a chunk finished processing.

But the waiting was worth it. Every time the Oracle—J.D.’s tongue-in-cheek name for the recovery software he’d written—spat out something new, they learned something ranging from fascinating to invaluable.

Whenever they ran into a particularly stubborn problem and were ready to chalk it up as a loss, the Oracle would offer up some key insight or bit of code that would propel them further along. Future Them seemed to have no compunction about reaching back with a helping hand to guide them forward.

There were exceptions. Part of what they recovered turned out to be plaintext messages from themselves. Sometimes they were jokes (“time humor” as J.D. took to calling it), and occasionally they bordered on the inane (“you’ll never guess who Mason’s sister hooks up with.”)

That last one had put Mason in a foul mood. He’d stormed around the lab and complained bitterly: “What’s the deal?? Where the fuck are all the lotto numbers and stock tips?”

J.D. patiently reminded him that they wouldn’t be able to send anything back that would change how things played out this time through. Mason grabbed a worn tennis ball from the floor and flopped back in his chair. He started bouncing it off a nearby wall and continued to grumble. “Hell with that. When it’s my turn, I’m sending back all the cheats I can.”

J.D. sighed. Mason was a top-shelf coder, but he didn’t have the same instinct for the knotty science of it that he and Ada had developed. “I’m sure you will,” he replied. “Hey, you know what? That’s probably what sets off the glitch that nukes half our data.”

“Wait, what? What’s that mean?” Just then, a door slammed shut behind them, and they both turned around to see Ada walking in, balancing a tall cup of something Starbucks on a stack of binders. “Hey, Ade, impeccable timing. I think J.D.’s accusing me of sabotage. Or intent to sabotage.” She cocked an eyebrow at him from across the lab.

“Come on, you’re supposed to know this stuff by now,” implored J.D. “One of the most fundamental tenets of modern physics is that causality is always preserved. If someone seems like they’re about to violate it—say, by sending back lottery numbers that we know you never actually receive—then something is going to stop him.

“That much we know for sure. The speculative part is what exactly the ‘something’ would be, but our best guess is that in the absence of any other selection effect, it tends to be some confluence of high-entropy events. Like your flash drive cuts out at the exact right instant to make sure your lotto numbers are wiped—and who knows what else gets fried as collateral damage.

“It’s good not to think of your intended action as ‘causing’ something to step in and stop it, though. Whatever happens was going to happen all along, precisely because events couldn’t have played out any other way.” He paused, looking for any sign of recognition on Mason’s face. “You seriously don’t remember how this works? Dr. Abel and I spent all last fall fleshing it out, and you were cc’d on everything.”

“You know how many of those goddamned emails you’ve cc’d me?” Mason stopped bouncing the ball as Ada pulled up a chair and was lost in thought for a moment. “Wait, yeah, now that you mention it, that rings a bell. Problem is, haven’t we already violated causality? The Oracle has been dropping hints since day one. We never would have figured out half this shit on our own.”

Ada jumped in: “Never? There’s a huge difference between ‘not ever’ and ‘not quickly.’ All the problems we’ve had help with so far strike me as the sorts of things we’d be able to crack on our own, sooner or later…” She trailed off, looking confused. “But J.D., I’ve got to admit that I don’t see why sending back code is okay, but lotto numbers isn’t.”

Mason was clearly delighted. He did a fist pump and shouted, “HA! See? I knew Ade had my back.”

J.D. shrugged indifferently, and said, “Look, if nothing else, we know that’s how it works because that’s what happened—will happen. We have code. We don’t have stock tips. I’ll admit I was surprised myself when the answers started coming in, but the bottom line is that they did, so it must not be breaking the rules.”

This still seemed like a contradiction, but Mason knew he wouldn’t get anywhere by arguing it, so he decided to stick with being an ass. “If you’re right, and I was the problem, isn’t it kind of a good thing? I mean if it was ’cause of me trying to send sensitive shit backwards, I just won’t do it this time. Then we get our complete transmission.”

J.D. started to laugh. Ada turned to him in mock exasperation. “He is kidding, right? He realizes that if it is his fault, there’s nothing he could ‘do differently this time,’ right?”

“I get what you kids are saying, but hang on, hear me out,” insisted Mason. “The past is the past and there’s nothing anyone can do about it, even with time travel. I get that, I really do. But now you’re trying to tell me the future is the past, too? If what’s done is done, and what will happen must happen, seems to me like past and future are kind of munging together. I mean, what the hell happened to self-determinism?”

“It is so too early for this conversation,” muttered Ada, standing up and grabbing her coffee. J.D. appeared lost in thought; Mason looked on expectantly. After about a minute, he spoke.

“Well, it’s complicated,” he began…

### 22 September 2022

Abel stared out the car window and saw nothing but rolling hills. He wasn’t sure what he’d been expecting. Perhaps to be escorted by several sunglassed men to a private Air Force jet and then whisked off to peril and excitement.

Instead, Shaffer had driven him in a rental to the airport, where they’d spent two hours waiting in line; apparently not even USAF colonels were above the purview of the TSA. When Abel made a crack about their flying coach, Shaffer looked at him coldly and explained that he’d visited the professor on his own recognizance. It seemed that Abel was not the military’s last best hope after all, but one avenue of attack among many.

Abel had tried repeatedly to ferret more information out of the colonel, but he’d remained tight lipped since leaving the university, brushing off Abel’s inquiries with a promise that Abel would “be briefed on the ground.” They’d touched down at SFO an hour ago, had taken the I-80 past Berkeley and kept right on going, so it seemed like a good time to ask where they were heading.

“Travis Air Force Base. We would have preferred somewhere more secure, but when we approached J.D. with our offer for relocation and protection, he was adamant about not going anywhere farther away than that. In fact, he wouldn’t consider any move at all until we sat him down and played back some of the death threats.”

“I credit you for getting that much. J.D.’s not the most flexible person I’ve met,” the professor said.

Shaffer glanced over at him. “No kidding. ‘Course, unless we can figure out what happened down there, I suppose the whole thing is moot.”

“‘What happened’? You’re U.S. military. You’re supposed to have the most advanced surveillance tech in the world.”

“Oh, we do. But–” He checked the GPS. “Look, we get to Travis in about twenty minutes. I’m sure they’ll answer all your questions to your satisfaction once we’re there.”

Abel was mollified. He’d waited this long for answers; he could wait a little more. Having barely slept on the plane, he closed his eyes and tried to catch a few winks.

Abel jolted awake to find they were at a guard station, the gate raising in front of them. An airman waved them forward, two others standing alertly nearby, M-16s in hand. Shaffer guided the car down a freshly paved road until they rolled to a stop outside one of the smaller buildings. Shaffer turned off the engine and told Abel to stay put, then left and approached two more MPs standing at attention by a door speckled with rust and peeling paint.

Abel blinked sleep from his eyes and took the opportunity to survey his surroundings. They’d passed a couple dozen buildings of varying size, some sleek and new. By contrast, the dilapidated hangar before him had seen better days. He guessed it was built back in the ’80s. He didn’t know why they were stopping here, but suspected it wasn’t their final destination.

As Shaffer approached the hangar, the two guards stepped into his path. Shaffer handed them some sort of ID. He pointed back towards Abel in the car, who felt strangely self conscious as the guards looked his way. One of them had a brief conversation on a walkie, and then returned the ID, visibly relaxed. Shaffer beckoned Abel over.

As he drew close, he began to say something but was cut short by Shaffer holding up his hand. Shaffer took out his phone and keyed in a code, and the nearby door unlocked audibly. Abel followed him inside, the guards issuing a smart salute as they passed.

The door clicked shut behind them, and Abel tried again. “Well, we’re here. So, where are we?” The hangar they’d walked into seemed to be in an even worse state of disrepair on the inside. There were oil-stained tarps covering what he took to be jeeps or humvees, and cobwebs floated idly in musty corners. It was the last place he would expect to find the most cutting-edge research on the planet.

Shaffer read the confusion on his face. “It’s not much to look at, I know. Ordinarily the Air Force frowns on security through obscurity, but we make do with what we have. The ID I gave them was mostly for show; they would have checked my ident broadcast before we got anywhere close.” His words echoed off the hangar walls.

“We have teams of guards,” he said conversationally, “stationed outside every building on this base, but they don’t know which one houses the lab. Officially, it’s still considered classified that J.D. is even at Travis. We never expected that to hold up for long, though; we were only trying to keep the media from sniffing around.”

As they walked, Abel became aware that the path they were tracing looked well-used, free of the dust and dirt that coated most of the hangar. Shaffer continued: “Actually, this is one of three buildings that serve as access points to the lab complex, which itself is completely underground. Security may have seemed light when really it’s anything but; these days, the majority of our safeguards are either fully automatic or remotely operated”—he paused to point out several oppressive-looking minigun turrets mounted on the ceiling that Abel had overlooked—”and if that makes things appear lax, so much the better.”

They reached a worn elevator door and stepped inside. Three plain buttons shone dully on the panel: G, B1, B2. Rather than press one, the colonel tapped something on his phone, and the elevator lurched suddenly downwards at a surprising speed. Some twenty seconds later they came to an abrupt stop, and Shaffer lead the way through the sliding door into a fluorescent-lit long, narrow hallway. Closed circuit cameras gazed down from the ceiling every couple of meters. Several more guards—Abel couldn’t tell what rank they were, but noticed additional stripes on their insignia—saluted as they walked by, evidently expecting them. Abel felt vaguely embarrassed. A guard at the end of the hall opened a door for them, and they passed through.

One look and Abel knew he had reached the complex proper. Every surface was a pristine white; it smelled of purified air and taxpayer dollars. He wouldn’t call it spacious, but he could tell everything had been laid out carefully to make it a comfortable environment. All of the interior walls were spotless glass, and he stood in a corridor that ran around the outer edge of a central cluster of lab rooms extending up and down several levels. A generous number of large touch-response terminals had been installed in the desks and walls, a few with autostereo displays better than anything he’d seen on the market. Peering into the nearest lab, he saw much equipment he recognized, and a few unfamiliar pieces. Perhaps a dozen techs were scattered about in ones and twos, drinking coffees or Mountain Dew and working intently at their stations, most either oblivious to or ignoring their arrival.

After Abel had time to take this in, Shaffer steered him down one of the hallways toward a large octagonal room where a severe-looking middle-aged brunette was studying a screen built into the matching large octagonal table. Shaffer gestured to the door. “Vicky’ll get you up to speed. I have some things to take care of,” he said, and walked away.

Abel pushed the door open tentatively and entered the room. Without looking up, the woman said, “Thanks, you can leave it on the table.”

“I’m sorry?”

Startled, the woman looked up. “Oh! Dr. Abel, my apologies, I was expecting—come in, come in.” She stood up and shook hands. “A pleasure to meet you. Go ahead and have a seat. My name is Victoria Stone; I’m the director here. Would you like any coffee? Tea? How was your flight in?”

Abel settled heavily into a chair. “I—the flight was fine. Tea would be wonderful. And you can call me Arthur.”

Vicky pushed a button on the desk. “Tea in Conference B, please.” She folded her hands and looked carefully at Abel, sizing him up. “It really is a pleasure to meet you. You know, we considered bringing you on board when we started up. I suppose that’s no big surprise given your reputation in the field. Anyway, the only reason we didn’t approach you earlier was at Dr. Driscoll’s explicit request—he never did explain his objection, but he was really very stubborn.”

Abel was momentarily lost; it had been a long time since he’d heard J.D.’s real name. “I’m not sure whether to be flattered or offended.”

Vicky chuckled politely. “You know how he is. You can ask him about it yourself if you find him. At any rate, I’m glad we’ve got you here now. I’m not sure how much you were already told, but we find ourselves at a bit of a loss.”

Abel hesitated. Something had been bugging him since Shaffer first walked into his classroom, and he decided to finally voice it. “Ms. Stone, I appreciate there’s some kind of situation here, but to be perfectly honest, I’m not sure what I could possibly help you with. My background is in theoretical physics, not security.”

“In this case, it’s hard to tell where one ends and the other begins. I suppose I ought to back up. Walls,” she said to nobody in particular, and the five large outward-facing glass walls immediately turned opaque, light levels within the room adjusting automatically to compensate. Vicky started speaking in earnest.

“You were told about the threats on Dr. Driscoll’s life?” Abel nodded, and Vicky went on. “It’s partially true that we relocated him and his team for their own protection. But, naturally, their work itself was of critical interest to the U.S. government. There were endless debates over whether to militarize it, commercialize it, reserve it for humanitarian endeavors, and even whether it should be pursued, but the one thing that all of us could agree on was that so long as this project existed, we needed it on a very short leash.

“We’ve been following Driscoll’s research for months. We keep tabs on most high-tech university labs across the country as a matter of course, and we found out about their ‘transmission from the future’ not long after it happened. It was no problem getting copies of their schematics, and we reproduced their equipment precisely, but at that point they’d only figured out how to receive, not transmit. And since it seemed that no more transmissions were forthcoming, the most valuable asset remaining was that one actual burst of information that they’d picked up from the future.

“Problem was, Driscoll kept that data-burst encrypted at all times. We procured a copy, but our friends at the NSA informed us that the encryption was like nothing they’d ever seen. ‘Might as well be noise,’ or something like that. We speculated—and we turned out to be right, by the way—that one of those intact pieces of code that Driscoll recovered right at the outset was the algorithm for that encryption.”

The door opened. It was a perky blonde holding a folder and Abel’s tea. “Thanks, you can leave them on the table,” said Vicky, and the girl set them down and scurried out. Abel took a sip of the tea, and on some level he realized that it was delicious, but mostly he was busy digesting Vicky’s story.

“As I was saying, it became clear that we weren’t going to get anywhere without the willing participation of Driscoll and his team. We started work on this complex before we’d even approached them. Turned out that we finished right after they made their announcement. They were reluctant to leave Berkeley, but once–

BOOM. Story cuts out here.