The Dark Forest

by Liu Cixin

  “Less than three hours to go,” the commander said, looking at his watch. The dust cloud was actually a giant, thin satellite in orbit around the sun, its position constantly changing. When it eventually moved out of the space where the probe might pass through, another dust cloud would have to be created behind it.

  “Do you really hope we’ll catch up to it?” the pilot asked.

  “Why not? We’re making history!”

  “Won’t the thing attack us? We’re not soldiers. This really ought to be done by the fleet.”

  Then their spacecraft received a message from the Ringier-Fitzroy Station reporting that the Trisolaran probe had entered the dust cloud and left a wake, and that precise parameters had been calculated for its trajectory. Blue Shadow was ordered to move immediately to rendezvous with and closely track the target. The station was more than one hundred AU away from Blue Shadow, meaning the message was delayed more than ten hours in transit, but the key had made an impression in the mold. Orbital calculations had even taken into account the effect of the thin dust cloud, so a rendezvous was just a matter of time.

  Blue Shadow set a course in accordance with the probe’s path and once again entered the invisible dust cloud, this time heading in the direction of the Trisolaran probe. It was a long flight this time, and over the course of more than ten hours, both pilot and commander grew sleepy. But the continuously shrinking distance between them and the probe kept them on edge.

  “I see it! I see it!” the pilot shouted.

  “What are you talking about? There’s still over fourteen thousand kilometers to go!” rebuked the commander. The naked eye could not possibly see a truck at a distance of fourteen thousand kilometers, even given the transparency of space. But soon he saw it for himself: On the trajectory described by the parameters, against the silent backdrop of space, a point of light was in motion.

  After a moment’s thought, the commander understood: The cloud of dust larger than the sun had been unnecessary, since the Trisolaran probe had restarted its engines and was continuing to decelerate. It did not intend to skip through the Solar System. It would remain here.

  * * *

  Because it was only a temporary measure in the fleets, the ceremony for handing over captain’s permissions on Natural Selection was a simple and low-key affair attended only by Captain Dongfang Yanxu, Acting Captain Zhang Beihai, First Vice-Captain Levine, and Second Vice-Captain Akira Inoue, as well as a special team from the General Staff Department.

  Despite this era’s technological development, they had still not managed to overcome the stagnation of fundamental theory, so Natural Selection’s permissions transfer was done via means Zhang Beihai was familiar with: three-factor retina, fingerprint, and passphrase authentication.

  Once the General Staff team had finished resetting the pupil and fingerprint data that identified the captain in the system, Dongfang Yanxu surrendered her pass phrase to Zhang Beihai: “Men always remember love because of romance only.”

  “You don’t smoke,” he replied calmly.

  “And the brand was lost during the Great Ravine,” she said with a trace of disappointment, and lowered her eyes.

  “But the password’s a good one. Not many people knew it back then either.”

  The captain and vice-captains exited, leaving Zhang Beihai alone to update the password and obtain complete control over Natural Selection.

  “He’s clever,” Akira Inoue said when the door to the spherical cabin vanished.

  “Ancient wisdom,” Dongfang Yanxu said, watching the spot where the door had disappeared, as if trying to see through it. “We’ll never be able to learn the stuff he brought from two centuries ago, but he can learn what we know.”

  Then the three of them remained silent and waited. Five minutes passed, clearly too long for changing a password, especially since Captain-in-waiting Zhang Beihai had come through training as the most skilled command system operator out of all the members of his Special Contingent. Five more minutes passed. The two vice-captains began swimming impatiently in the corridor, but Dongfang Yanxu remained silent and motionless.

  At last the door reappeared. To their surprise, the spherical cabin had turned black. Zhang Beihai had a holographic star map pulled up on which the labels had been blocked, leaving only the twinkling stars. From the doorway, he seemed to be suspended outside the spaceship, with his interface floating alongside him.

  “I’m done,” he said.

  “Why did it take so long?” Levin grumbled.

  “Were you relishing the thrill of gaining Natural Selection?” Akira Inoue asked.

  Zhang Beihai said nothing. He didn’t look at the interface, but gazed off instead at a star in a distant part of the map. Dongfang Yanxu noticed that a green light was flashing in the direction he was looking.

  “That would be ridiculous,” Levin said, picking up from Akira Inoue. “May I remind you that the captainship still belongs to Colonel Dongfang? The acting captain is just a firewall. I’m sorry to be rude about it, but that’s pretty much the truth.”

  Akira Inoue said, “And this state won’t last for very long. The investigation of the fleet is nearing an end, and it’s basically been proven that the Imprinted don’t exist.”

  He was about to go on, but was stopped by a low gasp of surprise from the captain. “Oh, god!” she said, and the two vice-captains, following her eyes, noticed Natural Selection’s current status on Zhang Beihai’s interface.

  The warship had been set into remote control mode, thereby bypassing the check for deep-sea state prior to Ahead Four. Outside communication had been severed. And, finally, most of the captain’s settings for putting the ship into maximum propulsion were in place. With the push of just one more button, Natural Selection would head off at maximum speed to the target selected on the map.

  “No, this can’t be happening,” Dongfang Yanxu said, her voice so low only she could hear it. It was for her own ears, in response to her earlier “god” exclamation. She had never believed in the existence of God, but now her prayers were real.

  “Are you insane?” Levin shouted. He and Akira Inoue rushed toward the cabin, only to crash into the bulkhead. There was no door, just an oval-shaped section of wall that had turned transparent.

  “Natural Selection is about to proceed to Ahead Four. All crew must enter deep-sea state immediately,” Zhang Beihai said, every word in his solemn, calm voice lingering in the air like an ancient anchor standing in the chill wind.

  “This is impossible!” Akira Inoue said.

  “Are you Imprinted?” Dongfang Yanxu asked, quickly calming herself.

  “You know that’s not possible.”

  “ETO?”

  “No.”

  “Then who are you?”

  “A soldier carrying out his duty to fight for humanity’s survival.”

  “Why are you doing this?”

  “I’ll explain after acceleration is complete. I repeat: All crew must enter deep-sea state immediately.”

  “This is impossible!” Akira Inoue repeated.

  Zhang Beihai turned around and, without so much as looking at the two vice-captains, stared straight at Dongfang Yanxu. His eyes instantly reminded her of the emblem of the Chinese Space Force, bearing swords and stars alike.

  “Dongfang, I said that I would be sorry if I had to kill you. There’s not much time.”

  Then the deep-sea acceleration fluid appeared within Zhang Beihai’s spherical compartment, forming into balls in the weightless environment. Each liquid globe, containing his distorted reflection along with the interface and the star map, began to combine into larger ones. The two vice-captains looked at Dongfang Yanxu.

  “Do as he says. The whole ship will enter deep-sea state,” the captain said.

  The two vice-captains stared at her. They knew what the consequences were for proceeding to Ahead Four outside of the deep-sea protective state: The body would be plastered to the bulkhead by a force 120 times that of Earth gravit
y. First blood would burst out under the immense weight, spreading into a thin layer of impossibly huge, radially patterned blood stains, and then the organs would be squeezed out, forming another thin layer that would be pressed together with the body into an ugly Dali painting.…

  As they left for their cabins, they issued orders to the entire ship to enter a deep-sea state.

  “You’re a well-qualified captain.” Zhang Beihai nodded at Dongfang Yanxu. “This shows maturity.”

  “Where are we going?”

  “Wherever we’re going, it’s a more responsible choice than staying here.”

  And then he was submerged in the deep-sea acceleration fluid, and Dongfang Yanxu could only make out a murky body through the liquid now filling the spherical compartment.

  Floating in the translucent liquid, Zhang Beihai recalled his diving experience in the navy two centuries before. He had never imagined that the ocean would be so dark a few dozen meters down, but that undersea world gave him the same feeling he later found in space. The ocean was space in miniature on Earth. He tried breathing, but his reflexes made him violently cough up liquid and residual gas, and his body shifted with the recoil. Still, there wasn’t the suffocation that he had anticipated, and as cool liquid filled his lungs, the oxygen it contained was supplied to his blood. He could breathe freely, like a fish.

  On the interface suspended in the liquid, he saw that the deep-sea acceleration fluid was filling each occupied compartment in the spaceship in turn. The process continued for more than ten minutes. His consciousness began to blur as the breathing liquid was injected with a hypnotic component that put everyone aboard ship into a state of sleep so as to avoid damage to the brain from the high pressure and relative hypoxia generated by acceleration at Ahead Four.

  Zhang Beihai felt his father’s spirit alight on the spaceship from the beyond, becoming one with it. He pressed the button on the interface, issuing in his mind the command that he had been working toward his entire life:

  “Natural Selection, Ahead Four!”

  * * *

  A small sun appeared in Jovian orbit, its bright light washing out the phosphorescence of the planet’s atmosphere. Dragging the sun behind it, the stellar-class warship Natural Selection eased out of the Asian Fleet base and accelerated rapidly, casting shadows of the other warships—each dark spot big enough to contain the Earth—onto the Jovian surface. Ten minutes later, a larger shadow was flung onto Jupiter like a curtain drawn across the giant planet. Natural Selection was passing Io.

  It was at this point that the Asian Fleet High Command confirmed the incredible fact that Natural Selection had defected.

  The European and North American Fleets issued protests and warnings to the Asian Fleet under the initial impression that it was an unauthorized move to intercept the Trisolaran probe, but they soon realized from Natural Selection’s heading that this was not the case. It was headed in the opposite direction from the Trisolaran invasion.

  The various systems hailing Natural Selection gradually let up after receiving no response. The high commands began to deploy pursuit and intercept ships, although they soon realized that little could be done about the defector warship. Bases on four of Jupiter’s moons possessed sufficient firepower to destroy Natural Selection, but they would not take that path, because it was quite likely that only a small minority of those on board, or even a single individual, had actually defected, and the two thousand-odd soldiers in deep-sea state were merely hostages. Commanders at the gamma-ray laser base on Europa could only watch as the small sun flew across the sky and into outer space, sprinkling Europa’s vast ice sheets with light like burning phosphorus.

  Natural Selection crossed the orbits of sixteen Jovian moons, and achieved escape velocity by the time it reached Callisto. Seen from the Asian Fleet base, the small sun gradually shrank, turning into a bright star that remained faintly visible for a week, as a reminder from the stars of the lasting pain of the Asian Fleet.

  Since the pursuing force had to enter deep-sea state, it took forty-five minutes after Natural Selection left for those ships to launch, lighting up Jupiter with another six suns.

  At Asian Fleet Command, which had stopped rotating, the commander silently faced the giant dark side of Jupiter as lightning flashed in the atmosphere ten thousand kilometers below him. Powerful radiation from the fusion engines of Natural Selection and the pursuing force had caused atmospheric ionization and lightning. The fleeting lightning strikes illuminated the surrounding atmosphere, visible at this distance as halos in constantly changing locations, turning the surface of Jupiter into a pond spattered with fluorescent rain.

  * * *

  Natural Selection accelerated in silence to one-hundredth the speed of light, the point of no return for its fusion fuel consumption. Now unable to return to the Solar System under its own power, it had become a lonely boat bound to forever wander in outer space.

  The commander of the Asian Fleet gazed at the stars trying unsuccessfully to find one in particular, for all there was in that direction was the faint light of the pursuers’ fusion engines. A report soon came in: Natural Selection had stopped accelerating. A while later, Natural Selection restored communication with the fleet. Then the following communication took place, with delays of more than ten seconds between transmissions due to the fact that the ship was now over five million kilometers away:

  NATURAL SELECTION: Natural Selection calling Asian Fleet! Natural Selection calling Asian Fleet!

  ASIAN FLEET: Natural Selection, Asian Fleet reads you. Report your status.

  NATURAL SELECTION: This is acting captain Zhang Beihai. I’ll speak directly to the fleet commander.

  FLEET COMMANDER: I’m listening.

  ZHANG BEIHAI: I take full responsibility for Natural Selection’s breakaway voyage.

  FLEET COMMANDER: Is anyone else responsible?

  ZHANG BEIHAI: No. Responsibility is mine alone. The situation has nothing at all to do with anyone else aboard Natural Selection.

  FLEET COMMANDER: I want to talk to Captain Dongfang Yanxu.

  ZHANG BEIHAI: Not now.

  FLEET COMMANDER: What is the ship’s current status?

  ZHANG BEIHAI: All is good. Every crew member is still in deep-sea state, apart from me. Power systems and life support are operating normally.

  FLEET COMMANDER: And your reasons for this treason?

  ZHANG BEIHAI: I may have deserted, but I am no traitor.

  FLEET COMMANDER: Your reasons?

  ZHANG BEIHAI: Humanity is certain to lose on the battlefield. I only want to save one of Earth’s stellar-class spaceships to preserve a seed of human civilization in the universe, a scrap of hope.

  FLEET COMMANDER: That makes you an Escapist.

  ZHANG BEIHAI: I’m just a soldier fulfilling his duty.

  FLEET COMMANDER: Have you received the mental seal?

  ZHANG BEIHAI: You know that’s not possible. That technology wasn’t around when I went into hibernation.

  FLEET COMMANDER: Then your unusually resolute defeatist beliefs are baffling.

  ZHANG BEIHAI: I don’t need the mental seal. I am the master of my beliefs. My faith is resolute because it doesn’t come from my own intelligence. At the beginning of the Trisolar Crisis, my father and I began to seriously consider the most basic questions about this war. Gradually, a group of deep-thinking scholars, including scientists, politicians, and military strategists, gathered around him. They called themselves the Future Historians.

  FLEET COMMANDER: Was it a secret organization?

  ZHANG BEIHAI: No. They studied very basic questions, and their discussions were always conducted in the open. The government and military even came forward and held several academic conferences on Future History. And it was from their research that I arrived at the mind-set that humanity is doomed.

  FLEET COMMANDER: But the theories of Future History have since been proven incorrect.

  ZHANG BEIHAI: Sir, you underestimate them. They not only pre
dicted the Great Ravine but the Second Enlightenment and Second Renaissance as well. What they predicted for today’s era of prosperity is virtually indistinguishable from the real thing. And, finally, they predicted that humanity would be totally defeated, wiped out in the Doomsday Battle.

  FLEET COMMANDER: Have you forgotten that you’re on a spaceship capable of traveling at fifteen percent of the speed of light?

  ZHANG BEIHAI: Genghis Khan’s cavalry attacked with the speed of twentieth-century armored units. The mounted crossbow of the Song Dynasty had a range of up to fifteen hundred meters, comparable to twentieth-century assault rifles. But it’s impossible for ancient cavalry and crossbows to compete with modern forces. Fundamental theory determines everything. The Future Historians clearly saw this point. You, on the other hand, have been blinded by the dying radiance of low-level technology and are luxuriating in the nursery of modern civilization, without any mental preparation whatsoever for the coming ultimate battle that will determine the fate of humanity.

  FLEET COMMANDER: You come from a great army, one that was victorious over an enemy with far more advanced equipment. It won victory in one of the largest land wars in the world, relying solely on seized weapons. Your behavior is a disgrace to that army.

  ZHANG BEIHAI: My dear commander, I’m more qualified than you to speak of that army. Three generations of my family served in it. During the Korean War, my grandfather attacked a Pershing tank armed with a grenade. The grenade hit the tank and slid off before exploding. The target was barely scratched, but my grandfather was hit by machine-gun fire from the tank, had both legs broken under its treads, and spent the rest of his life an invalid. But compared to two of his comrades, who were crushed to a pulp, he was lucky.… It’s that army’s history that so clearly taught us the significance of a technological gap during wartime. The glory you know is what you’ve read in the history books, but our trauma was cemented by the blood of our fathers and grandfathers. We know more than you do what war means.

  FLEET COMMANDER: When did you conceive of your treasonous plan?

  ZHANG BEIHAI: I repeat: I may have deserted, but I am not a traitor. I conceived of the plan the last time I saw my father. I saw in his eyes what I needed to do, and it took me two centuries to realize my plan.