Death's End

by Cixin Liu

  “Who are you talking about?” asked Vadimov.

  “Everyone! The human race! Half a century ago, we walked on the moon. But now, we have nothing, can’t change anything!”

  Cheng Xin bent down and picked up the document. Indeed, it was the interim feasibility report. She and Vadimov flipped through it, but it was highly technical and difficult to skim. Wade had also returned to their circle—the PDC secretary had informed him that the session would begin in fifteen minutes.

  Camille calmed down a bit in the presence of the PIA chief. “NASA has conducted two small tests of nuclear pulse propulsion in space, and you can read the results in the report. Basically, our proposed spacecraft is still too heavy to reach the required speed. They calculate the entire assembly needs to be one-twentieth its proposed mass. One-twentieth! That’s ten kilograms!

  “But wait, they also sent us some good news. The sail, it turns out, can be reduced to under ten kilograms. They took pity on us and told us that we can have an effective payload of half a kilogram. But that is the absolute limit, because any increase in the payload will require thicker cables for attachment to the sail. Every additional gram in the payload means three more grams of cables. Thus, we’re stuck with zero point five kilograms. Haha, it’s just like our angel predicted: light as a feather!”

  Wade smiled. “We should ask Monnier, my mother’s kitten, to go. Though, even she would have to lose half of her weight.”

  Whenever others were happily absorbed by their work, Wade appeared gloomy; when others were forlorn, he became relaxed and jokey. Initially, Cheng Xin had attributed this quirk to part of his leadership style. But Vadimov told her that she didn’t know how to read people. Wade’s behavior had nothing to do with his leadership style or rallying the troops—he just enjoyed watching others lose hope, even if he himself was among those who ought to be in despair. He took pleasure in the desperation of others. Cheng Xin had been surprised that Vadimov, who always tried to speak of others generously, held such an opinion of Wade. But right now, it did look as though Wade took pleasure in watching the three of them suffer.

  Cheng Xin felt weak. Days of exhaustion hit her at once, and she sank to the lawn.

  “Get up,” said Wade.

  For the first time, Cheng Xin refused to obey an order from him. She remained on the ground. “I’m tired.” Her voice was wooden.

  “You, and you,” Wade said, pointing to Camille and Cheng Xin. “You’re not allowed to lose control like this in the future. You must advance, stop at nothing to advance!”

  “There’s no way forward,” said Vadimov. “We have to give up.”

  “The reason you think there’s no path forward is because you don’t know how to disregard the consequences.”

  “What about the PDC session? Cancel it?”

  “No, we should proceed as though nothing has happened. But we can’t prepare new documents, so we have to orally present the new plan.”

  “What new plan? A five-hundred-gram cat?”

  “Of course not.”

  Vadimov’s and Camille’s eyes brightened. Cheng Xin also seemed to have recovered her strength. She stood up.

  Accompanied by military escort vehicles and helicopters, an ambulance departed with the Fourth Wallfacer. Against the lights of New York City, Wade’s figure appeared as a black ghost, his eyes glinting with a cold light.

  “We’ll send only a brain,” he said.

  Excerpt from A Past Outside of Time

  The Staircase Program

  In fourteenth-century China, during the Ming Dynasty, the Chinese navy invented a weapon called Huolong Chu Shui, literally meaning “fiery dragon issuing from water.” This was a multistage gunpowder rocket similar in principle to antiship missiles of the Common Era. The missile itself (Huolong) was augmented with booster rockets. When launched, the booster rockets propelled the missile toward the enemy ship by flying just above the surface of the water. As the booster rockets burnt out, they ignited a cluster of smaller rocket arrows stored inside the missile, and these would shoot out the front, causing massive damage to enemy ships.

  Ancient warfare also saw the use of repeating crossbows, which prefigured Common Era machine guns. These appeared in both the West and the East, and Chinese versions have been discovered in tombs dating from the fourth century B.C.

  Both of these weapon systems were attempts to utilize primitive technology in novel ways that demonstrated a power incongruous for their time period.

  Looking back, the Staircase Program implemented at the beginning of the Crisis Era was a similar advance. Using only the primitive technology available at the time, it managed to boost a small probe to 1 percent of lightspeed. This achievement should have been impossible without technology that would not appear for another one and a half centuries.

  At the time of the Staircase Program, humans had already successfully launched a few spacecraft outside the Solar System and had managed to land probes on Neptunian satellites. Thus, the requisite technology to distribute nuclear bombs along the acceleration leg of the probe’s course was relatively mature. But controlling the flight path of the probe to pass by each bomb, and detonating each at the precise moment, posed great technical challenges.

  Every bomb had to detonate just as the radiation sail passed it. The distance from each bomb to the sail at the moment of the explosion ranged from three thousand to ten thousand meters, depending on the bomb’s yield. As the probe’s velocity increased, the timing needed to be more precise. However, even as the sail’s speed reached 1 percent of lightspeed, the margin for error remained above the nanosecond range, well achievable by the technology of the time.

  The probe itself contained no engine. Its direction was entirely determined by the relative positions of the detonating bombs. Each bomb along the route was equipped with small positional thrusters. As the sail passed each bomb, the distance between them was only a few hundred meters. By adjusting this distance, it was possible to alter the angle between the sail and the propulsive force generated by the nuclear explosion, and thus control the direction of flight.

  The radiation sail was a thin film, and the only way to carry the payload was to drag it behind in a capsule. The entire probe thus resembled a giant parachute—except that the parachute flew “upwards.” To avoid damage to the payload from the nuclear explosions occurring three to ten kilometers behind the sail, the cables connecting the sail to the payload had to be very long: about five hundred kilometers. An ablative layer protected the payload capsule itself. As the nuclear bombs exploded, the ablative material gradually vaporized, cooling the capsule as well as lowering the total mass.

  The cables were made from a nanomaterial called “Flying Blade.” Only about a tenth of the thickness of a strand of spider silk, the cables were invisible to the naked eye. Eight grams of the material could be stretched into a cable one hundred kilometers long, yet it was strong enough to securely pull the payload capsule during acceleration, and would not break from the massive radiation generated by the nuclear explosions.

  Of course, Huolong Chu Shui was not, in fact, equivalent to a two-stage rocket, and the repeating crossbow was not the same as a machine gun. Similarly, the Staircase Program could not bring about a new Space Age. It was only a desperate attempt that drew upon everything humanity’s primitive level of technology could offer.

  Crisis Era, Years 1–4

  Cheng Xin

  The mass launch of Peacekeeper missiles had been in process for over half an hour. Trails from six missiles merged together, and, lit up by the moon, resembled a silvery road that reached into heaven.

  Every five minutes, another fiery ball ascended this silvery road into the sky. Shadows cast by trees and people swept along the ground like the second hands of clocks. This first launch would involve thirty missiles, sending three hundred nuclear warheads with yields ranging from five hundred kilotons to 2.5 megatons into orbit.

  At the same time, in Russia and China, Topol and Dongfeng miss
iles were also rising into the sky. The scene resembled a doomsday scenario, but Cheng Xin could tell by the curvature of the rocket trails that these were orbital launches instead of intercontinental strikes. These devices, which could have killed billions, would never return to the surface of the Earth. They would pool their enormous power to accelerate a feather to 1 percent of the speed of light.

  Cheng Xin’s eyes filled with hot tears. Each ascending rocket lit them up like bright, glistening pools. She told herself again and again that no matter what happened next, it was worth it to have pushed the Staircase Program this far.

  But the two men beside her, Vadimov and Wade, seemed unmoved by the spectacular scene playing out before them. They didn’t even bother looking up; instead, they smoked and conversed in low voices. Cheng Xin knew very well what they were discussing: who would be chosen for the Staircase Program.

  The last session of the PDC marked the first time a resolution had been passed based on a proposal that wasn’t even written down. And Cheng Xin got to witness the debating skills of Wade, usually a man of few words. He argued that if we assumed the Trisolarans were capable of reviving a body in deep freeze, then it made sense to assume they were also capable of reviving a bare brain in similar condition and conversing with it through an external interface. Surely such a task was trivial for a civilization capable of unfolding a proton into two dimensions and etching circuits over the resulting surface. In some sense, a brain was no different from the whole person: It possessed the person’s thoughts, personality, and memories. And it most definitely possessed the person’s capacity for stratagems. If successful, the brain would still be a ticking bomb in the heart of the enemy.

  Although the PDC members did not fully agree that a brain was the same as a whole person, they lacked better choices, especially since their interest in the Staircase Program was largely based on the technology for accelerating the probe to 1 percent of lightspeed. In the end, the resolution passed with five yeses and two abstentions.

  Once the Staircase Program was approved, the problem of who should be sent came to the forefront. Cheng Xin lacked the courage to even imagine such a person. Even if his or her brain could be captured by the Trisolarans and revived, life afterwards—if such an existence could be called life—would be one interminable nightmare. Every time she thought about this, her heart felt squeezed by a hand chilled to minus-two-hundred-degrees Celsius.

  The other leaders and implementers of the Staircase Program did not suffer her pangs of guilt. If PIA were a national intelligence agency, this matter would have been resolved long ago. However, since PIA was only a joint intelligence committee formed by the permanent member nations of the PDC, after the Staircase Program was revealed to the international community, the issue became extremely sensitive.

  The key problem was this: Before launch, the subject would have to be killed.

  After the initial panic of the Crisis subsided, a mainstream consensus gradually dominated international politics: It was important to prevent the Crisis from being leveraged as a tool to destroy democracy. PIA personnel were instructed by their respective nations to be extra careful during the process of selecting potential Staircase Program subjects and not commit political errors that would embarrass their countries.

  Once again, Wade came up with a unique solution to the difficulty: advocating, through the PDC and then the UN, the passage of euthanasia laws in as many countries as possible. But even he wasn’t confident that this plan would work.

  Of the seven permanent members of the PDC, three quickly passed euthanasia laws. But these laws all clearly provided that euthanasia was only available to those suffering terminal illnesses. This was not ideal for the Staircase Program, but it seemed the outer boundary of political acceptability.

  Thus, candidates for the Staircase Program had to be chosen from the population of terminally ill patients.

  * * *

  The thunderous noises and bright lights in the sky faded. The missile launches had come to an end. Wade and a few other PDC observers got into their cars and left, leaving only Vadimov and Cheng Xin.

  “Why don’t we take a look at your star?” he said.

  Four days ago, Cheng Xin had received the deed to DX3906. She was utterly surprised and fell into a delirium of joy. For a whole day, she kept on repeating to herself: Someone gave me a star; someone gave me a star; someone gave me a star.…

  When she went to see Chief Wade to give a status report, her happiness was so palpable that Wade asked her what the matter was with her. She showed him the deed.

  “A useless piece of paper,” he said, and handed it back to her. “If you’re smart, you should drop the price and resell it right away. Otherwise you’ll end up with nothing.”

  But Cheng Xin wasn’t bothered by his cynicism—she had already known what he was going to say. She knew very little about Wade except his work history: service in the CIA, then deputy secretary of Homeland Security, and finally here. As for his personal life, other than the fact that he had a mother and his mother had a kitten, she knew nothing. No one else did, either. She didn’t even know where he lived. He was like a machine: When he wasn’t working, he was shut down somewhere unknown.

  She couldn’t help but bring up the star to Vadimov, who enthusiastically congratulated her. “Every girl in the world must be jealous,” he said. “Including all living women and dead princesses. You’re certainly the first woman in the history of humankind to be given a star.” For a woman, was there any greater happiness than to be given a star by someone who loved her?

  “But who is he?” Cheng Xin muttered.

  “Shouldn’t be hard to guess. He must be rich, for one thing. He just spent a few million on a symbolic gift.”

  Cheng Xin shook her head. She’d had many admirers and suitors, but none of them were that wealthy.

  “He’s also a cultured soul. Stands apart from the crowd.” Vadimov sighed. “And he just made a romantic gesture that I’d call fucking ridiculous if I read it in a book or saw it in a movie.”

  Cheng Xin sighed as well. A much younger Cheng Xin had once indulged in rose-tinted fantasies that the Cheng Xin of the present would mock. This real star that appeared out of nowhere, however, far exceeded those romantic dreams.

  She was certain that she knew no man like that.

  Maybe it was a secret admirer from afar who, on impulse, decided to use a tiny part of his vast wealth to indulge in a bit of whimsy, to satisfy some desire she would never understand. Even so, she was grateful.

  That night, Cheng Xin climbed onto the top of One World Trade Center, eager to see her new star. She had carefully reviewed the materials that accompanied the deed explaining how to find it. But the sky in New York was overcast. The next day and the day after were the same. The clouds formed a giant teasing hand that covered her gift, refusing to let go. But Cheng Xin wasn’t disappointed; she knew she had received a gift that couldn’t be taken away. DX3906 was in this universe, and it might even outlast the Earth and the Sun. She would see it, one day.

  She stood on the balcony of her apartment at night, gazing up at the sky and imagining her star. The lights of the city below cast a dim yellow glow against the cloud cover, but she imagined her star giving the clouds a rosy glow.

  In her dream, she flew over the star’s surface. It was a rose-colored sphere, but instead of scorching flames, she felt the coolness of a spring breeze. Below her was the clear water of an ocean, through which she could see swaying, rose-colored clouds of algae.…

  After she woke up, she laughed at herself. As an aerospace professional, even in her dreams she couldn’t forget that DX3906 had no planets.

  On the fourth day after she received the star, Cheng Xin and a few other PIA employees flew to Cape Canaveral to attend the launch ceremony for the first batch of missiles. Achieving orbit required taking advantage of the Earth’s spin, and the ICBMs had been moved here from their original deployment bases.

  The trails left behind by
the missiles gradually faded against the clear night sky. Cheng Xin and Vadimov reviewed the observation guide for her star. Both had had some training in astronomy, and soon they were looking at the approximate location. But neither could see it.

  Vadimov took out two pairs of military-issue binoculars. With them, it was easy to see DX3906. After that, even without the binoculars, they could find the star. Cheng Xin stared at the faint red dot, mesmerized, struggling to comprehend the unimaginable distance between them, struggling to translate the distance into terms that could be grasped by the human mind.

  “If you put my brain on the Staircase Program probe and launched it at the star, it would take thirty thousand years to get there.”

  Cheng Xin heard no response. When she turned around, she saw that Vadimov was no longer looking at the star with her, but leaning against the car and looking at nothing. She could see that his face was troubled.

  “What’s wrong?”

  Vadimov was silent for some time. “I’ve been avoiding my duty.”

  “What are you talking about?”

  “I’m the best candidate for the Staircase Program.”

  After a momentary shock, Cheng Xin realized that Vadimov was right: He had extensive experience in spaceflight, diplomacy, and intelligence; he was steady and mature.… Even if they were able to expand the pool of candidates to include healthy individuals, Vadimov would still be the best choice.

  “But you’re healthy.”

  “Sure. But I’m still running from my responsibility.”

  “Have you been pressured?” Cheng Xin was thinking of Wade.

  “No, but I know what I must do; I just haven’t done it. I got married three years ago, and my daughter just turned one. I’m not afraid to die, but my family matters to me. I don’t want them to see me turned into something worse than a corpse.”

  “You don’t have to do this. Neither the PIA nor your government has ordered you to do this, and they can’t!”