Haden had never seen so much wealth in one place before. He stopped short at the balcony and stared down in awe. Behind him, the click of boot heels on polished slate grew louder as the Nuvoy Manufacturing Guards closed in. Their pace was steady and certain. There was nowhere for him to run.

The air had the electrified scent of ozone and left the taste of dust in his mouth. Light filtered down through skylights frosted to block the prying cameras of spy satellites and surveillance drones. Shelves lined the walls and rose in tiers from the islands that dominated the floor below him. Robots moved between the islands, stacking and removing items, loading pallets onto the automated carts that darted from one side of the room to the other, all moving so quickly and choreographed so precisely that a human would have been run over or decapitated by a swinging arm within seconds of entering. Carts exited continually with stacks of goods to some point beneath Haden's feet, but more carts kept entering through the large doorway at the distant end of the room, bearing every imaginable type of commodity and numerous finished products to be sorted and stocked by the robot workers.

"Only empty trucks ever enter the Nuvoy compound," Jenna used to tell him, "but they're always full when they leave. So where does everything come from?"

As Haden watched, the carts brought in more and more and still more. Trailer-sized canisters of liquid helium. Massive, chained bundles of mahogany logs. Barrel after barrel of crude and synthetic oil. Crates of frozen shark and whale meat, half-ton cubes of scandium and antimony and zinc, boxes of the element dysprosium. And the real reason for this room and the compound that housed it, a pyramid of huge chests taking up half an acre of floor space, each chest bearing a label that in one word explained the reason for the war and what would be required to win it: "Phosphate."

Then his eye was caught by a collection of finished products on one of the closest islands. Sitting on the middle shelf was an entire bin of Thyvix capsules. Enough of the drug to have kept Jenna alive for years. He stared at it and barely moved as two guards stepped up on either side of him.

"Haden Kahenda," one of the guards said near his ear. The steel jaw of a handcuff locked around his left wrist. "How far did you think your falsified credentials would get you?"

Haden twisted his body to face him, adrenaline washing away his memories and regrets. "I hoped they would get me here."

The guard yanked Haden's other arm back and cuffed his wrists together. "Search him."

The guard who had spoken was too tall for his company-issued uniform. He held his fists near his sides like a pair of clubs. His companion had the stunted stature that marked her immediately as a survivor of famine. She patted Haden down. In his waistband she found a white plastic cylinder a little wider and squatter than a pen. A mini disrupter. She looked at it without recognition and slipped it into her pocket. "If you knew enough about Nuvoy to get through security, you know about the Nuvoy Act," she said.

There was no point now in trying to maintain his cover. "I used to be a Nuvoy contractor."

"Then you know that on this compound we're an authorized police force. We can detain you for up to 24 hours before we hand you over to the Virginia State Police."

Haden looked her in the eye. "I want to talk to Jonathan Greene."

"What a coincidence," she answered. "He wants to speak with you."

Jonathan Greene, president and CEO of Nuvoy Manufacturing, was having lunch in his private office suite. Haden's captors pushed him forward so that he stood in front of the table in Greene's dining room while the CEO leaned back from his plate and wiped his hands with a cloth napkin, looking him over as if examining a perplexing report. "You're the energy consultant."

For a moment, when Greene's hand had passed over the table, images had appeared on the surface. Menu options. Fresh fruit pastries. A green salad. A grilled-rare steak. The products of fertilizer, water, and wealth that most people had thought they had lost forever before Nuvoy made them possible again.

"What are you doing here, Kahenda?" he demanded. His voice was soft but insistent.

Haden didn't answer.

"You did good work for us. If you needed another job, you could have asked."

For some reason, Haden thought of Jenna's Thyvix tablets. Nuvoy could give you anything you needed, until suddenly it didn't, and when it stopped was when you realized how much depended on a single corporation. "I came to find out what happened to the fusion plant I designed."

Greene frowned. "That's classified. This facility is crucial to the war effort."

"You're not connected to the grid, and your solar farm isn't big enough for your operations. So you must be drawing additional power from somewhere."

Greene's voice hardened in an instant. "You're trespassing. You potentially compromised national security by breaking into the Warehouse."

"The reactor I worked on—"

"Nuvoy's reactor." Out of the corners of his eyes, Haden saw both guards tense, waiting for a cue from their boss.

"I saw the leaked memo that says Nuvoy developed transmutation technology. But the trucks coming into the compound are empty, so what's being transmuted?"

"Our work is classified. I'm giving you one last chance to explain your presence here."

A young man with downcast eyes entered the room, picked up Greene's plate, and shuffled back out. The man bore the same telltale and familiar signs of stunting as the female guard. It was impossible to forget that if Nuvoy hadn't ended the North American famines, everyone born since then would have looked like that.

Which was probably why no one wanted to ask the obvious questions. "Whatever you're doing here must require energy. So where is it coming from?"

Greene rose slowly. "You're a corporate spy. That, or just a traitor."

A cold fist closed over Haden's stomach. "I'm neither. I'm an engineer. You know that."

"You spies," Greene said, "you thieves, you want to steal instead of create. Our country is at war. The whole world is fighting for cropland. You can't get more food without fertilizer and there's not enough fertilizer without phosphorous. There are countries trying to reclaim phosphorous from their sewage systems and their people die of starvation anyway. But we produce more. Every day. And you think I'll just give up our methods?"

"I'm not a spy."

"It's not just phosphorous. Why do you think we're winning the war? Because the Pentagon's contractors can keep building advanced weapons systems, while our enemies have to dig up landfills to find rare earths, or make it a crime to throw away their electronics instead of recycling them. The Pentagon has what it needs because of us. It comes from Nuvoy."

There was no point in provoking Greene further. "Maybe I should just be on my way. I'm proud of the work I've done for Nuvoy in the past and I'm willing to leave it at that."

Greene motioned toward a side door. "Keith, take him down to lockup."

The detention rooms were in the basement of a building near the middle of the compound. The guards were silent as they removed Haden's cuffs and directed him into the cell.

"How long are you going to keep me here?" Haden asked.

The woman opened her mouth to respond, but her companion glared at her, and she kept quiet as they swung the door shut. Haden heard the electronic click of the lock.

It was a bare room, hardly larger than a closet, with no furniture. The only object it contained was a pink plastic bucket. Weak light came from bulbs behind four ceiling panels. It was clearly not designed for long-term occupancy.

Haden tested the door and the ceiling panels. Though not a real prison, there was no way out until his captors wanted him out. He paced, and his thoughts returned to the bin of Thyvix.

Nuvoy had given Haden a bottle of Thyvix for Jenna when he was contracted to them for the power plant. The pills couldn't be found in stores, and they were marked with the logo of a company that they'd never heard of and wasn't on the Internet. The pills ran out at about the same time Haden's contract did, and his contact claimed he was unable to get more.

It was while she was housebound, toward the end, that Jenna started wondering how Nuvoy had been able to procure a drug that didn't otherwise seem to exist. Which led to the bigger question: how did Nuvoy function at all? First she read all the exposés she could and spent time on message boards and in chat rooms. The leaks about Nuvoy's supposed transmutation technology had just come out. When the news articles didn't answer her questions, she started looking up Nuvoy's patents.

"The memo about the transmutation device is fake," Jenna announced one evening. "A tech writer in Cleveland apparently traced the leak back to Jonathan Greene's office, but then Nuvoy sued him to take his posts down."

"They sued him to prevent him from saying a leak they'd complained was false really was false?" Haden had known he didn't have much time left with her, so he had made her interests his.

"Complaining about the memo was part of their attempt to raise its profile."

A few days later she had another announcement. "I've figured it out."

Haden had been watching a documentary of the pre-Nuvoy years, when the first food riots had struck major American cities. "Figured what out, hon?"

"I've been looking up all of Nuvoy's patents. Both theirs and their subsidiaries. The hardest part was just figuring out who all the subsidiaries are."

By that time Jenna was no longer able to rise from the bed. She spent most of her time humming to herself while she read her tablet. Haden walked into the room and sat beside her.

"Most of their patents don't seem to have anything to do with their main business," Jenna said. "Unless you put them together and see how they fit. Nuvoy created a teleporter."

He stared at her.

"If the technology really exists, it opens a wormhole across space-time. They could get to any other place on Earth instantly, if they were able to set up a portal there first."

Now, pacing the cell, Harden realized he was humming the same song she'd sung to herself almost constantly during those last few weeks. He had never heard it before, and she'd claimed not to know where it came from. "Where will I go? Left and down, and back to where I started. Right and up, and down again."

Haden was still pacing and humming when the lock clicked. He went and pressed his ear against the door, and then pushed. It opened. The hall was empty. The guard or someone she'd passed it off to had brought the disrupter into the control center, and evidently it had done its job.

Haden knew the compound's general layout from satellite images. A small building abutted the Warehouse's north wall. Few people went in or out, and it was always guarded. From the balcony, however, it had appeared to be the source of the carts and forklifts that kept the Warehouse stocked.

He followed a series of underground passages and found his way back to the Warehouse and into a ground-floor corridor that paralleled the main room. He was almost to the door that led to the attached building when he heard the lock's bolt slide home. Nuvoy's IT technicians must have realized what the disrupter was doing and shut it off.

"Kahenda," a voice behind him said. He turned.

"You're persistent," Greene told him. "But you've come to the end of the road. There's nowhere else for you to go. So you might as well give me the truth. What are you here for?"

Haden scanned the area for an escape route. But the door behind him had a swipe pad that required an unlock pattern to open. A moment later a squad of seven guards entered the wide corridor and fanned out behind Greene. They were armed with semiautomatic pistols and stun batons.

"We can still use your skills," Greene said. "Maybe you can work for us again. I don't have to press charges." He watched Haden's face. "You would have to remain onsite, of course, now that you've seen this Warehouse."

Haden didn't move.

"What do you want? If it exists, I can get it for you. No one else can promise what I can."

Haden thought of Jenna, diving in a smooth parabola back when she was fully healthy, her body sliding into the blue-glowing reactor water without a splash and then swimming powerfully down to repair the valves. It was the first time he had ever seen her. It was a job that robots hadn't been able to do yet, and for the afternoon of work she had received a year's salary. She was brilliant and risk-taking and strong. "I want to have had the chance to say goodbye to my wife before she died."

"I'm sorry you lost her. But think of all the other wives and husbands you could help by coming back to us." Greene took a step closer. "Without us the country wouldn't get fed, Haden."

"If you want me to consider working with you, I need answers." Haden gestured toward the shelves beyond the wall. "Where does all of this come from?"

Greene's eyes hardened and he planted his feet. "I built all of this so we can eat and survive and maybe win our war. If you can look outside and still not think that's enough of an answer for you, then there's no reason for you to be here. We already have state troopers at the gate waiting to take you to jail."

Haden spun back and lunged for the door. "Stop!" one of the guards shouted. "Step back with your hands up!" The pounding of boots told him that the other guards were surging forward.

Haden stabbed his finger against the swipe pad, unsure about what to do next. Then a familiar tune came to his head. "Left and down, and back to where I started. Right and up, and down again." Haden swiped his finger left, down, diagonally up to the right-hand corner, and then down once more. The bolt retracted and the door slid open. Haden ran through it.

He was in a building that consisted of one large room. The air was dim, and once again he smelled dust and ozone. Two men sat behind a glass partition that blocked off the area in front of the western wall, studying a bank of monitors. Robotic carts emerged in a constant stream from a huge gate in the middle of the floor and followed a path of painted stripes and orange cones to the doorway that led to the Warehouse. When he looked through the gate, he saw a line of robotic carts waiting to come through, but when he looked past or around the gate, the floor behind it was empty. As Haden ran toward the gate he heard a buzzing sound, and the smell of ozone grew stronger. The scene through the gate wavered, as if he were looking at it through a haze of desert heat.

"Stop now!" the guard behind him bellowed.

"No! Don't shoot! Don't shoot near the portal!" Greene yelled.

Haden leapt through the gate. He felt an electric tingling across his skin, and then he was on the other side. He ducked behind the rumbling wagons and kept them between himself and the glass-walled control center as he headed for a door marked "Exit" at the end of the room. There was an armed guard in this version of the room, and there were still two people behind the glass—women instead of men—but none of them saw him. Haden reached the exit and pushed through. He was outside.

The disc of the sun burned through a dust-darkened sky. Haden breathed in the gritty air and coughed. At first glance the compound looked the same as when he had first arrived earlier that day, but when he did a second take he saw changes everywhere. One of the smaller buildings was gone. Others were taller, or had additional wings. All of the structures were covered in different sidings or paint coats than he remembered, and each of them, even the ones he'd never seen before, looked beaten by weather and age. But the most notable update was an entirely new building adjacent to the one he'd just left, in the place where a fenced-off construction site had appeared in satellite images. He recognized it as soon as he turned his head back and saw it, because he had helped design it. It was Nuvoy's fusion power plant.

A near-ceaseless stream of wagons trundled in through the compound's main gate and split into two branches, one proceeding into the Warehouse and the other into the portal building. A secondary stream carried goods back out of the Warehouse to join the carts on their way to the portal. Empty wagons headed back to the gate. Workers were stationed at points along the main route, but other than the large Nuvoy logo nothing about their uniforms was familiar. They wore blue-gray coveralls along with masks, the latter apparently to filter out the dust.

Haden ducked into a shaded corner between the power plant and the portal building to avoid being seen and planned his next move. Even out of the direct path of the sun the heat was a weight on his body, and his clothes already clung to his flesh with sweat. He quickly forgot about his discomfort, however, as his eyes fell upon two signs.

The first was a poster. "NOTICE," it read in large letters. "INTRUDER from the TARGET SITE. Notify COMMAND immediately if spotted. Apprehend and secure if possible." He looked between the words and the accompanying photo several times, as if expecting one of them to change, but no matter how much he stared the picture remained the same. It was an image of him.

The other sign was metal and affixed to the wall next to the portal building entrance:

WARNING

DO NOT PASS THROUGH PORTAL

DO NOT ENTER TARGET SITE

LETHAL LEVELS OF RADIATION IN USE

Beneath the words was the universal symbol of radiation.

Radiation poisoning. He had radiation poisoning.

The first thought that came to his mind wasn't his mortality, but Jenna's. He had held her hand when she died. They had stretched the Thyvix to make it last longer, but finally there was nothing left to stretch. Her final decline came so suddenly that by the time he realized it was the end she was no longer responsive, and he never knew if she heard any of the things he whispered as he lay beside her.

After her body was taken away he sat for hours on the empty bed, trying to relive every moment they had shared in the room. It was late evening before he stood up. Only then did he open the drawer in the nightstand next to the mattress that still held the void of her impression. He was looking for something he was afraid to find, but nothing was there. The drawer was as empty as the bed.

Now he shook his head as if the motion could physically clear his mind. He had to concentrate on avoiding the Nuvoy guards. He used the carts as cover and made his way to the compound's gate.

The world outside the wall was as gray as the glowering sky. He had traveled to Nuvoy that morning over a boulevard bordered by trees and parks. Instead of that broad street he now walked beside a strip of asphalt, surrounded by a desert of clay and sand. Thistles and dry grasses crunched under his feet. The suburb he had passed was gone, along with any sign that buildings had once stood there. When he glanced back he saw the compound looming like a fortress over a lunar landscape.

Against this bleak backdrop there was constant motion. Carts filled the broken road, heading toward the compound laden with goods and returning empty. Every sixth vehicle was an automated tank. Men and women in masks and Nuvoy uniforms were posted at guard towers at regular intervals, fingering assault rifles and scanning the horizon. An airstrip occupied a hill just to the north, above which one plane circled while several more were lined up on the tarmac waiting to depart. Nuvoy workers unloaded boxes and bundles from the cargo plane at the front of the line and hefted them onto yet more empty wagons.

The guards glanced at Haden from their towers, determined he wasn't a threat, and looked away. Occasionally he passed the skeletons of carts that looked as though they had been twisted by explosions. His feet started dragging. He felt weak and slow and nauseous, but he didn't know if that was because of the heavy heat or the smoky air, or the radiation in his blood. Depending on the dosage, he knew what he had to look forward to. Diarrhea, dizziness, vomiting. Within a day he would start having trouble making decisions. Within a month he would be dead.

Unless I get Thyvix. But Thyvix or no, his body wouldn't be able to take a second trip through the portal.

He crested a hill and looked down at the city of Tyson's Corner. It was in ruins. Had it fallen in the war? As he approached he realized the buildings hadn't been bombed; they had been stripped. He stumbled forward on increasingly weak legs, periodically stopping to retch and then moving again, staring. Windows gaped open, all the glass removed. The metal facades of buildings had been torn off. Light bulbs were gone from streetlamps.

There were people living in the hollowed office towers. They were the first people Haden had seen since passing through the portal who weren't wearing Nuvoy uniforms. A few rode bikes, but most walked, or watched him suspiciously from the gloom of lightless rooms. They almost all wore Nuvoy masks, even the children, and everyone he saw looked emaciated. Next to the buildings that seemed the most heavily populated were large water tanks with prominent Nuvoy logos on their sides.

Finally he stopped, exhausted, and put his hands on his knees as a wave of sickness made his stomach and intestines clench. When the attack passed his stomach still churned, but he was able to draw his breath back in and straighten his back.

"This is the future," he told himself out loud, to make it real.

He stood back up. Whenever this was, he would need Thyvix or another equally powerful medication to survive. And there was one obvious place to look for it.

He walked toward one of the compound-bound carts, wondering whether he had the strength to jump on and hitch a ride. A siren blasted from the vehicle as soon as he got within a couple of yards.

"Stop, thief," an electronic-sounding voice boomed from the closest tank. Haden lurched to a quick halt and turned to face the tank, perhaps twenty yards away, as its gun spun on its turret to face him. "You are at risk of violating Nuvoy property. Step back or I will be forced to terminate you."

Haden took a step back. After a moment the tank rejoined the convoy on rumbling treads.

He trudged back to the compound. He had to pause several times to catch his breath or wait out a spell of dizziness. When he reached the gate he noticed for the first time how much wider and taller the walls were than when he had originally entered. The concrete was pitted and blackened. Automated guns swiveled toward him as he approached, and he stopped. He shouted until concealed speakers crackled to life. "Nuvoy doesn't accept visitors," a prerecorded voice announced. "You are welcome to access our customer service chatbot. Thank you for your interest."

"My name is Haden Kahenda," Haden announced loudly. "I want to see Jonathan Greene." He didn't know whether Greene was still alive, or what he'd do if he weren't. But a few minutes later a guard stepped into view and motioned him inside.

After Haden reentered the compound, he was surrounded by a small phalanx of guards and searched. This time, at least, he wasn't handcuffed. The guards led him to the executive building he had last been in half a day and decades earlier.

The inside of the building had been updated from refined to opulent. The surfaces were dressed in gleaming marble. Fixtures and doorframes were gilded. The air had been scrubbed of impurities. The employees who stepped aside for them in the halls wore comfortable-looking clothes rather than the uniforms that were ubiquitous outside. Haden and his escort passed the elevator that led to the CEO's suite and kept walking.

The guards stopped and stood at attention as a man in an elegant suit walked by. He strode through the hallway with an air of command, but just after he passed he glanced back at Haden as if trying to place him. It was the butler who had taken Greene's plate in the dining room. Now he was much older, with a fuller face and figure. A moment later he stepped into the CEO elevator and was gone.

The guards brought Haden to a small office with no windows. Greene stared at him. "Wow." He shook his head and stood up. He looked tired and frail, a mannequin of skin and bones lost within his Nuvoy coveralls. "You're exactly the same as when you entered the portal thirty years ago." He turned to the guards. "You can leave us. Mr. Kahenda is an old friend."

After they were alone, Haden asked, "So the future is paying for the past. How long can this be sustained?"

"It can't," Greene said. "If I were still in control I wouldn't have let it get this far. Nuvoy is wealthier now than it's ever been, but I don't know how any civilization outside these walls can ever recover."

"The war is over?"

"No. Somewhere America's machines and our enemies' autonomous forces are still destroying each other. But there's no one left with the power to stop Nuvoy. Everyone who thought they could has already tried."

"Then stop it yourself," Haden said. "End this."

Greene looked past Haden to the wall. "When I first created the portal decades ago and the first bot and its message came through, I assumed that I was the one who was on the other side, pulling the strings. I thought that here I was in control." He sighed. "But it's Donovan. He took over little by little, and he's openly been CEO for the past ten years or so. He needs me to make sure my younger self is able to build the company and doesn't get suspicious, and if it weren't for that, he would have sent me out to the camps years ago. Or just killed me." He said it matter-of-factly. "I've tried to send messages to my past self, but obviously I didn't figure them out, because here I am. But I have to keep trying, until I get caught and Donovan kills me regardless of my modest value to him."

"If you could talk to him—"

"I'm a prisoner." Greene's instinctive impatience and self-certainty blazed through the indignities of his frailty and situation. "I might look comfortable, but I can't leave. Still, maybe we can help each other." He met Kahenda's gaze. "I offered you a position years ago, and I'm prepared to do it again. We're no longer able to maintain the fusion reactor, so we're using a series of incinerators, but they're inefficient. I could use your expertise in the long term, but more importantly, I can use your help now."

"Jonathan—" He wanted to explain that he wasn't going to live long enough to improve Nuvoy's power plants, but Greene cut him off again.

"You can help me return to power. I've written myself a note warning about Donovan's plans and I've bribed a Source Room technician to recalibrate the portal settings at my signal so that one of the shipments goes back to an earlier time. I've just been waiting for an opportunity. If this fails everyone involved will be executed, but if it succeeds I'll be back in control—and I will make sure you're rewarded commensurately."

It only took a few seconds for Haden to decide what to do. "I'll deliver it the control center for you. If you can get me Thyvix."

Greene stared at him. "Of course. You came through the portal. You're sick." He nodded thoughtfully. "I can get you a year's supply, at least. Maybe more."

"I need it now."

"That's fine. I'll see what I can do. In the meantime, I have a security guard uniform that should get you to the portal room, so let's make sure it fits."

"I'm not doing anything until I get a Thyvix capsule." Greene looked irritated, but Haden's knees buckled and he collapsed into a silk-cushioned chair. Greene immediately turned to speak to someone through a cylindrical device on his desk. A short time later a man came in with a paper-wrapped package. After the man had left, Greene unfolded the paper and placed a Thyvix pill in Haden's hand. He walked to another room and came back with a glass of water. Haden swallowed it down. The water was cold and sweet. He clenched the armrests until the room stopped spinning and he was able to lift his head.

"The company that made Thyvix operated for about five years," Greene said. "Their products were in demand, but eventually people could no longer afford them and they could no longer get the necessary supplies." He handed Haden a manila envelope. "The letter. Enter through the Warehouse. Don't stop, don't speak to anyone. All you have to do is get to the Source Room and wait until the portal display shows the year 2063. It will stay at that year for five minutes. Drop the letter into any of the carts heading into the portal. That's all you have to do."

"How will I get into the Source Room? Is the swipe code the same?"

"Yes. It was changed after you broke in, but at some point we reverted back to the default."

"Can you show me what it is?"

"You already know. You got into the room."

"I'd like you to go over it with me again. Just to be sure."

Greene's impatience was back on display, but he did as Haden asked.

"There was a guard in the portal room—"

"It will be taken care of. Don't speak to anyone, just complete your mission and then walk outside. If it worked, I'll be back in control, and I've added to the letter so that I'll be aware of the role you played. If it doesn't, none of this matters."

"Is there a trick to getting past the robots in the Warehouse safely?"

"Just avoid them. As I said, don't speak to anyone, don't stop. Just walk through and complete your mission."

"Okay." Haden was beginning to feel some of his strength coming back, even though his bones and muscles still ached and his stomach was still a knot. He used his arms to push himself back up to his feet.

"I haven't been out of these rooms in four years," Greene said. "But what I miss most isn't even my freedom. I miss the sub sandwiches I used to eat as kid." He sighed and shook his head. "You can't get the ingredients anymore. But when you're done, everything will be different. It will be the way it should be."

A few minutes later, walking toward the warehouse in the Nuvoy uniform, Haden knew Greene was wrong. He was lying to himself if he wasn't intentionally lying to Haden. Nothing would be different, because this was the system that Greene had designed.

Haden was grateful to escape the scorching sun and return to the warehouse's cool vastness. He patted the pocket that held the pen he had swiped as a weapon of last resort as he changed into the uniform. He entered beneath the balcony and immediately saw why Greene had been so dismissive of his safety concerns. Only about a quarter of the machines he had seen originally were still in use, and large stretches of the shelves were empty. The present had been stripped of its resources.

The island for finished products was almost directly in his path. He went to it and stopped in front of the Thyvix bin. It was mostly empty. There were a handful of pills at the bottom, enough for one person for about a year.

Haden thought of the date Greene had mentioned, 2063. That was about a year before Jenna had died.

Haden pulled open the envelope's flap and slid out the letter. He recognized the paper immediately. During the last week of Jenna's life, he had entered the bedroom to find her reading what looked like a handwritten note. He had walked in on her reading the same letter once before. Both times she quickly slid the paper into a drawer in her nightstand. What's that? he asked on the second occasion. Oh, nothing, she replied, looking away. Just something from an old friend.

"Hey!" someone shouted down from the balcony. "You! Who are you? Step away from the bin!"

Haden leaned over, reached in and grabbed the pills. He dropped them into the envelope.

"Stop! You! Don't move!"

Haden turned Greene's note over and wrote a message to Jenna. It was brief. It contained the code for the door to the portal room, explained where he was, and told her goodbye.

Behind him the door banged open. He heard the by-now familiar clatter of boots on the floor. He reinserted the paper into the envelope and pressed the seal back down, scratched out Greene's name, and in its place scrawled Jenna's name and address in care of his old Nuvoy project manager. Then he ran.

A guard caught up to him just before he reached the door. The guard grabbed his wrist and pulled it back to handcuff. Behind him now there were more guards, more footsteps and voices. Haden fought free, raced to the door and entered the code. The guard grabbed him again, and again Haden tore free and burst through the door. He saw everything in an instant: the portal, with the year 2063 displayed on the screen above it, and a cart lumbering through. Haden threw the envelope onto the cart and turned to the face the guards charging into the room. Out of the corner of his eye, he saw the cart pass through into the past.

"Goodbye," he said to Jenna, out loud even though she was decades away, and smiled as the guards closed in.