by Cixin Liu
“Also, Luo Ji is on Pluto. He wants to see you.”
“Luo Ji? He’s alive?!” AA cried out.
“Yes. He’s almost two hundred.”
“All right. Let’s go to Pluto,” Cheng Xin said. In the past, this would have been an extraordinary journey. But now, nothing mattered.
A pleasant male voice spoke up. “Do you wish to go to Pluto?”
“Who are you?” asked AA.
“I’m Halo, or Halo’s AI. Do you wish to go to Pluto?”
“Yes. What do we do?”
“You just have to confirm the request. There’s no need to do anything. I will complete the voyage for you.”
“Yes, we want to go to Pluto.”
“Authorization confirmed. Processing. Halo will accelerate at 1G in three minutes. Please pay attention to the direction of gravity.”
Cao Bin said, “Good. Better leave early. After the attack alert is issued, there might be total mayhem. Hopefully we’ll get a chance to talk again.” He closed the window link before AA and Cheng Xin could say good-bye. At this moment, AA, Cheng Xin, and Halo were not his top priorities.
Outside the porthole, they could see a few blue reflections appearing on the shell of the combined city—reflections of Halo’s nozzle lights. Cheng Xin and AA fell to one side of the spherical hall and felt their bodies grow heavier. The acceleration soon reached 1G. After the two of them—still weak from hibernation—struggled up and looked outside the porthole again, they saw the entirety of Jupiter. It was still immense, and shrinking at too slow a rate to be perceived.
The ship’s AI led AA and Cheng Xin on a tour of the ship to familiarize them with it. Like its predecessor, this new Halo was still a small stellar yacht with a maximum capacity of four. Most of the space on the ship was taken up by the ecological cycling system. By conventional measures, the ecological cycling system was extremely redundant—a volume of space that would have supported forty was used to provide for only four. The system was divided into four identical subsystems, linked together and acting as each other’s backups. If any of the four failed accidentally, the other three could bring it back to life. Halo’s other distinguishing characteristic was the ability to land directly on a medium-sized solid planet. This was a rare design choice among stellar ships—similar ships typically used shuttles to carry landing parties onto planets. Directly descending into a planet’s deep gravity well required the ship to have a very strong hull, which greatly increased the cost. Moreover, the need for atmospheric flight required a streamlined profile, which was also very rare among stellar ships. All of these design features meant that if Halo could find another Earthlike planet in outer space, it could act as a habitable base for the crew on the surface of the planet for a considerable amount of time. Maybe it was these characteristics of Halo that led to it being chosen for the artifact-rescuing mission to Pluto.
There were numerous other unusual features on the yacht. For instance, it had six small courtyards, each about twenty to thirty square meters in size. Each courtyard automatically adjusted to the direction of gravity under acceleration, and, during coasting, spun independently within the ship to generate artificial gravity. Each courtyard displayed a different natural scene: a green lawn with a babbling brook running through the grass; a small copse with a spring in the middle; a beach with waves of clear water throwing up surf.… These scenes were small but exquisite, like a string of pearls made of the best parts of the Earth. On a small stellar spaceship, such a design was extremely luxurious.
Cheng Xin felt both distressed and sorry for Halo. Such a perfect little world was soon going to be turned into a slice without thickness. She tried to avoid thinking about those other grander things facing imminent destruction—annihilation covered the sky of her thoughts like a giant pair of black wings, and she dared not look directly up at it.
Two hours after departure, Halo received the formal dark forest attack alert issued by the Solar System Federation Government. The president, a beautiful woman who looked very young, made the announcement. She stood in front of the blue flag of the Federation and spoke without expression. Cheng Xin noticed that the blue flag resembled the ancient UN flag, though a diagram of the Sun replaced the diagram of the Earth. This most important document, marking the end of human history, was very short:
Five hours ago, the advance warning system confirmed that a dark forest strike has been initiated against our world.
The attack takes the form of a dimensional strike, which will collapse the space around the Solar System from three dimensions to two dimensions. The result will be the complete destruction of all life.
The process is estimated to take eight to ten days. At this moment, the collapse is ongoing and the rate and extent of collapse are rapidly growing.
We have confirmed that the escape velocity for the collapsing region is the speed of light.
An hour ago, the Federation Government and Parliament have passed a new resolution that repeals all laws regarding Escapism. However, the government wishes to remind all citizens that the escape velocity far exceeds the maximum velocity of all human space vehicles. The probability of a successful escape is zero.
The Federation Government, Parliament, the Supreme Court, and Federation Fleet will carry out their duties until the end.
AA and Cheng Xin didn’t bother to watch more news. It was possible that, just like Cao Bin said, the Bunker World had approached paradise. They wanted to see what paradise looked like, but they didn’t dare look. If everything was heading toward ruination, the more beautiful it all was, the more pain they would suffer. In any event, it was a paradise that was collapsing in the terror of death.
Halo stopped accelerating. Behind it, Jupiter became a small yellow dot. The next few days of the voyage were spent in the uninterrupted slumber produced by the sleep-aid machine. In this lonely voyage through the night before the end, just the unstoppable mad imaginings were enough to make anyone fall apart.
* * *
Halo’s AI awakened AA and Cheng Xin from their dreamless sleep as the ship reached Pluto.
Out of the porthole and on the monitor they could see the entirety of Pluto. Their initial impression of the dwarf planet was one of darkness, like an eye that remained perpetually shut. This far from the Sun, the light was extremely dim. Only when Halo entered low orbit could they see the colors on the surface of the planet: Pluto’s crust appeared to be made of patches of blue and black. The black was rocks—not necessarily black in color, but the light was too dim to tell otherwise. The blue was solidified nitrogen and methane. Two centuries ago, when Pluto had been near its perigee and inside Neptune’s orbit, the surface would have looked completely different. The ice cover would have partially melted and produced a thin atmosphere. From the distance, it would have appeared a deep yellow.
Halo continued to descend. On Earth, this would have involved a soul-stirring atmospheric reentry, but Halo continued to fly through the silent vacuum, decelerating by the power of its own thrusters. On the blue-black ground below, an attention-grabbing line of white text appeared:
EARTH CIVILIZATION
The text was written in the modern script that mixed Latin and Chinese elements. After it, there were a few more lines of smaller text repeating the same thing in different scripts. Cheng Xin noticed that none of them said “museum.” The yacht was still about one hundred kilometers above the surface, which meant that the text was gigantic. Cheng Xin couldn’t make an exact estimate of the size of the characters, but she was certain that these were the largest written characters ever produced by humankind, each big enough to contain a city. By the time Halo was only about ten thousand meters above the surface, one of the large characters took up the entire field of view. Finally, Halo touched down on the broad landing field, which was the topmost dot in the Chinese character qiu (球), a part of the word Earth.
With the guidance of the ship’s AI, Cheng Xin and AA put on light space suits and exited Halo onto the surface of Pluto
. Given the frigid surroundings, the heating systems in their space suits were operating at maximum power. The landing field was empty, white, and seemed to phosphoresce in the starlight. The numerous burn marks left on the ground indicated that many spacecraft had once landed and taken off here, but Halo was the only ship here now.
During the Bunker Era, Pluto was akin to Antarctica on ancient Earth. No one lived here permanently, and few came to visit.
In the sky, a black sphere moved rapidly among the stars. It was large, but the surface was shrouded in darkness: Charon, Pluto’s moon. Its mass was a tenth of Pluto’s, and the two almost formed a double-planet system, revolving around a common center of mass.
Halo turned on its searchlights. Due to the lack of atmosphere, there wasn’t a visible beam of light. It cast a circle of light on a distant rectangular object. This black monolith was the only protrusion above the white ground. It gave off an eerie sense of simplicity, as though it was an abstraction of the real world.
“That looks a bit familiar,” Cheng Xin said.
“I don’t know what it is, but I don’t have a good feeling about it.”
Cheng Xin and AA headed for the monolith. Pluto’s gravity was only one-tenth of the Earth’s, and so they proceeded by leaping. Along the way, they noticed a row of arrows pointing toward the monolith on the ground. Only when they reached the monolith did its immensity impress itself on their minds. When they looked up, it was as though a chunk had been taken out of the starry sky. They looked around and saw that there were rows of arrows coming from other directions, all pointing toward the monolith. At the foot of the monolith was another prominent protuberance: a metal wheel about a meter in diameter. To their surprise, they found the wheel to be hand-operated. Above the wheel was a diagram formed from white lines against the black surface of the monolith. Two curved arrows indicated the directions in which the wheel could be turned. Next to one of the arrows was a drawing of a half-open door, while the other bore a drawing of a shut door. Cheng Xin turned to survey the arrows on the ground pointing to the monolith. All the simple, clear, wordless instructions gave her a strange feeling, which AA voiced.
“These things … I don’t think they’re intended for humans.”
They turned the wheel clockwise. The wheel was stiff, but eventually a door opened in the surface of the monolith. Some gas escaped, and the water vapor within quickly deposited into ice crystals that glinted in the searchlight. They entered the door and saw another door facing them, also operated by a wheel. This time, there were simple written instructions above the wheel, informing them that they were in an air lock and needed to close the first door before opening the second. This was unusual, since as early as the end of the Crisis Era, pressurized buildings could open their doors directly to vacuum without needing an air lock.
Cheng Xin and AA turned the wheel on the inside of the door they had entered to shut it. The searchlight was cut off. They were about to turn on the lights on their space suits to hold off the terror of darkness when they noticed a small lamp in the ceiling of the narrow air lock. This was the first sign they had seen of electricity. They began to turn the wheel to open the second door. Cheng Xin was certain that even if they hadn’t closed the first door, they would still have been able to open the second. The only thing that prevented air from leaking was following the instructions. In this low-technology environment, there was no automatic mechanism to prevent errors.
The rush of air almost toppled them, and the rapidly warming temperature fogged their visors. But the space suits told them that the external air pressure and composition was breathable; they could open their helmets.
They saw a tunnel lit by a series of dim lamps heading into the earth. The dark walls of the tunnel swallowed up the dim light they emitted so that, between the cones of light, all was darkness. The floor of the tunnel was a smooth incline. Although the angle was steep, close to forty-five degrees, there were no stairs. This design was probably motivated by two considerations: There was no need for stairs in low gravity, or the path wasn’t meant for humans.
“There’s no elevator?” AA asked. She was frightened by the steep way down.
“An elevator might break down over time. This building was intended to last through geologic eons.” The voice came from the other end of the tunnel, where an old man appeared. In the dim light, his long white hair and beard floated in the low gravity. They seemed to be giving off their own light.
“Are you Luo Ji?” AA shouted.
“Who else? Children, my legs don’t work so well anymore, so forgive me for not coming up to meet you. Come on down by yourselves.”
Cheng Xin and AA descended the incline in leaps. Due to the low gravity, this wasn’t a very dangerous maneuver. As they approached the old man, they saw that he was indeed Luo Ji. He wore a long white changshan, a Chinese-style robe, and leaned against a cane. His back was slightly bowed, but his voice was hale and loud.
At the bottom of the incline, Cheng Xin bowed deeply. “Honored Elder, hello.”
“Haha, there’s no need for that.” Luo Ji waved his hands. “We used to be … colleagues.” He looked at Cheng Xin and in his eyes was a surprised delight that almost seemed incongruent with his age. “You’re still so young. There was a time when I saw you only as the Swordholder, and then, gradually, you became a lovely young woman. Haha.…”
In Cheng Xin’s and AA’s eyes, Luo Ji had also changed. The stately Swordholder was gone. They didn’t know that the cynical, playful Luo Ji in front of them now was a return to the Luo Ji from four centuries ago, before he had become a Wallfacer. That Luo Ji had returned, as if awakening from hibernation, but the passage of time had moderated him, and filled him with more transcendence.
“Do you know what has happened?” AA asked.
“Of course, child.” He pointed behind him with his cane. “Those idiots all left on spaceships. They knew that they ultimately couldn’t escape, but they still tried to run. Foolish.”
He meant the other workers in the Earth Civilization Museum.
“You and I have both busied ourselves for nothing,” said Luo Ji to Cheng Xin.
It took Cheng Xin a bit of time before she understood what he meant, but the flood of emotions and memories was interrupted by Luo Ji’s next words. “Forget it. Carpe diem has always been the right path. Of course there’s not much diem now for carpe, but we need not look for trouble. Let’s go. You don’t need to help support me. You haven’t even learned how to walk properly around here yet.”
Given Luo Ji’s advanced age of two hundred, the difficulty of locomotion under such low gravity wasn’t moving too slow, but too fast. The cane wasn’t so much a support as a decelerator.
After a while, space opened up before them. Cheng Xin and AA realized that they were now in a much wider and bigger tunnel—a cavern, really. The ceiling was high above, but the space was still only lit by a dim row of lights. The cavern looked very long, and the other end was not visible.
“This is the main body of the museum,” Luo Ji said.
“Where are the artifacts?”
“In the halls down at the other end. Those aren’t so important. How long can they keep? Ten thousand years? A hundred thousand years? A million, at the most. Practically all of them will have turned to dust by then. But these—” Luo Ji pointed around them. “—were intended to be preserved for hundreds of millions of years. Why, do you still think this is a museum? No, no one visits here. This is not a place for visitors. All of this is but a tombstone—humankind’s tombstone.”
Cheng Xin looked around the empty, dim cavern and thought back to all she had seen. Indeed, everything was filled with hints of death.
“How did such an idea come up?” AA looked all around.
“You ask that because you’re too young.” Luo Ji pointed to Cheng Xin and himself. “During our time, people often planned for their own gravesites while they were still alive. Finding a graveyard for humanity isn’t so easy, but erecting a tomb
stone is doable.” He turned to Cheng Xin. “Do you remember Secretary General Say?”
Cheng Xin nodded. “Of course.”
Four centuries ago, while she had worked for the PIA, Cheng Xin had met Say, the UN secretary general, a few times at various meetings. The last time was at a PIA briefing. Wade was there, too. On a big screen, Cheng Xin had given Say a PowerPoint presentation about the Staircase Project. Say had sat there quietly and listened to the whole thing without asking any questions. Afterwards, Say walked next to Cheng Xin, leaned in, and whispered, “We need more people to think like you.”
“She was a true visionary. I’ve thought of her often through the years. Could she really have died almost four hundred years ago?” Luo Ji leaned on the cane with both hands and sighed. “She was the one who thought of this first. She wanted to do something so that humanity would leave behind a legacy that could be preserved for a long time after our civilization was gone. She planned an unmanned ship filled with cultural artifacts and information about us, but it was deemed a form of Escapism, and the project halted with her death. Three centuries later, after the Bunker Project began, people remembered it. That was a time when people worried that the world was going to end any moment. The new Federation Government decided to build a tombstone at the same time that the Bunker Project was built, but it was officially referred to as the Earth Civilization Museum so as not to be seen as a sign of pessimism. I was named the chair of the tombstone committee.
“At first, we engaged in a large research project to study how to preserve information across geologic eons. The initial benchmark was a billion years. Ha! A billion. Those idiots thought that would be easy—after all, if we could build the Bunker World, how difficult could this be? But they soon realized that modern quantum storage devices, while capable of storing a whole library in a grain of rice, could only preserve the information without loss for about two thousand years. After that, decay would make it impossible to decode. As a matter of fact, that only applied to the highest-quality storage devices. Two-thirds of more common varieties failed within five hundred years. This suddenly transformed the project from a detached, contemplative matter into an interesting practical problem. Five hundred years was real—you and I came from only four hundred years ago, right? So the government stopped all work on the museum and directed us to study how to back up important data about the modern world so that it could be read in five hundred years, heh heh.… Eventually, a special institute had to be set up to tackle the problem so that the rest of us could focus on the museum, or tombstone.
