Chapter Summaries

A powerful storm flooded the area around the Luan Bird on Titan, but One and Zero confirmed the Starship and extraction equipment were safe. After Gao Yang and Zhao Zijie adjusted to the storm, the extraction pipe repeatedly detected and cleared a blockage on its own.

• One explained that a hurricane driven by Saturn's gravity and temperature differences had caused Titan's methane ocean to rise far beyond expectations.
• Zhao Zijie contacted Zero, who confirmed the storm would not harm the Luan Bird or its extraction equipment and would last three days.
• Gao Yang adapted to the storm and posted selfies, while Zhao Zijie asked him to take some photos too.
• One reported a blockage in the extraction equipment, but it cleared automatically and the system resumed operation.
• The blockage alarm sounded again, and Zhao Zijie shut down the equipment; minutes later, One reported that the blockage had cleared.

Zhao Zijie and Gao Yang discovered that giant jellyfish-like creatures were climbing onto and covering the Luan Bird starship in Titan’s Kraken-Mare Sea. After Zhao Zijie reported the swarm to Lü Yongchang, Lü asked them to catch one and bring it inside.

• Zhao Zijie and Gao Yang heard impacts on the Luan Bird and saw a pale yellow creature attached to its hull and climbing upward.
• More jellyfish-like creatures struck the starship, and Zhao Zijie and Gao Yang watched the swarm spread across the sea and cover the Luan Bird.
• Zhao Zijie contacted Lü Yongchang on Mars and sent him footage of the creatures, which averaged five meters in diameter.
• Lü told Zhao Zijie and Gao Yang to stay calm because the Luan Bird could withstand the creatures.
• Lü asked Zhao Zijie and Gao Yang to find a way to catch one of the jellyfish-like creatures and bring it inside.

Lü Yongchang investigated why the jellyfish were swarming over the Luan Bird Starship and discovered they were attracted to heat. After the storm receded, Zhao Zijie used the Hall Thruster to lure the jellyfish away, where the extreme heat destroyed them.

• Lü Yongchang ordered Zhao Zijie to capture jellyfish, and Zero’s robots brought several aboard after the jellyfish swarmed and overwhelmed one robot.
• Lü Yongchang tested a heater and discovered the jellyfish could detect temperature differences as small as 0.1 degrees Celsius from tens of meters away.
• Lü Yongchang told Zhao Zijie that a stronger heat source could draw the jellyfish away from the Starship and extraction equipment.
• After the hurricane and tide receded, Zhao Zijie activated the Hall Thruster, attracting the jellyfish to its nozzle, where the heat made them burst.

Zhao Zijie and Gao Yang learned that the methane-based jellyfish could help the crew produce methane and supply useful lubricant, so Lü Yongchang wanted to raise them. Half a month later, they set a heated trap during the next high tide, and a swarm of jellyfish rushed toward it.

• Zhao Zijie told Lü Yongchang that the jellyfish had died after he and Gao Yang used the Hall Thruster to heat them.
• Lü Yongchang explained that the jellyfish used acrylonitrile cell membranes, secreted a stable lubricant, and produced methane by breathing hydrogen and consuming acetylene.
• Lü Yongchang said he hoped to raise the jellyfish, and Zhao Zijie and Gao Yang anticipated catching them during future tides.
• Half a month later, Zhao Zijie and Gao Yang switched on a heater inside a wire-mesh cage outside the Luan Bird Starship during the second high tide.
• Jellyfish sensed the heat and surged toward the surface, while Gao Yang worried aloud that they might have killed too many of them.

Zhao Zijie and Gao Yang captured over a hundred jellyfish from Titan’s methane sea, but the creatures died after being kept in a holding pool. Lü Yongchang realized the pool’s surface-layer seawater might be responsible and ordered an insulated robot investigation of the seabed.

• Zhao Zijie and Gao Yang turned the heater back on to draw the overwhelming jellyfish swarm away from the Luan Bird, then collected the few that remained after the tide receded.
• Zhao Zijie ordered One to monitor the captured jellyfish in the holding room, where over a hundred lay motionless in a pool of Titan seawater.
• A few days later, Zhao Zijie and Gao Yang found that all the jellyfish had died, and surveillance footage showed they had remained inactive before their bodies began leaking yellow substance.
• Lü Yongchang ruled out problems with the simulated environment and seawater circulation, then realized the intake drew water from near the methane sea’s surface.
• Lü Yongchang told Zero to have Zhao Zijie send insulated robots to investigate the seabed.

Zhao Zijie and Gao Yang discovered that the Kraken-Mare Sea concealed a deeper, warmer Inner Sea beneath a thin layer of rock. Lü Yongchang proposed that the two oceans might connect somewhere, which could explain why the jellyfish could not survive in the Breeding Room.

• Zhao Zijie and Gao Yang sent three modified robots into the Kraken-Mare Sea to survey its seabed.
• The robots’ signal failed after the seabed opened into a vast, more than five-hundred-meter-deep chasm.
• Zhao Zijie and Gao Yang reported the discovery to Lü Yongchang, who said Titan’s ocean had an upper Kraken-Mare layer and a lower Inner Sea separated by thin rock.
• Lü Yongchang questioned why the jellyfish could not survive in the Breeding Room if they lived in the upper ocean.
• Gao Yang suggested that the two oceans might be connected somewhere.

After three robots unexpectedly escaped the inner ocean and transmitted their data, Lü Yongchang discovered that a cryovolcano connected it to the Kraken-Mare Sea. The robots survived a swarm of pale-yellow jellyfish, leaving Lü with new evidence about the ocean passage and its life.

• Zhao Zijie and Gao Yang detected a signal from the three robots and contacted Lü Yongchang after the robots began transmitting data.
• Lü Yongchang learned that the robots were only a hundred kilometers away and reviewed their recordings.
• The footage showed the robots traveling through a narrowing tunnel lined with complex organic substances before entering the Kraken-Mare Sea at a depth of about 250 meters.
• Lü Yongchang identified the passage as a cryovolcano connecting the inner ocean and the Kraken-Mare Sea.
• Lü Yongchang had Zero brighten the searchlights, revealing pale-yellow jellyfish around the vent, but Zero dimmed the lights before the creatures reached the robots.

Lü Yongchang concluded that the Titan jellyfish could not be farmed and ordered a culling plan to harvest them, while preserving the evidence and history of the decision. As the Glutton approached Titan, Bart revealed it carried fifty Black Lady Two craft, prompting Zhao Zijie to suspect what they would be used for.

• Lü Yongchang explained that the jellyfish depended on periodic cryovolcanic eruptions for food and habitat, so he abandoned the breeding plan and ordered a culling plan.
• Gao Yang worried that killing the jellyfish might prevent a future civilization, but Zhao Zijie argued that humanity had to act in its own interest.
• Lü Yongchang ordered Zero to preserve the jellyfish data in the Core Database and record the incident unaltered in the Chronicle of Human Civilization.
• The Glutton approached Titan, and Bart told Zhao Zijie that the supply ship carried fifty Black Lady Two craft for transporting methane.
• Zhao Zijie realized the craft might be connected to the culling plan.

Zhao Zijie commanded the Titan extermination operation, guiding fifty Black Lady Twos to lure jellyfish into Bart’s heated basin. The jellyfish began flooding into the killing apparatus, and Gao Yang started collecting their corpses.

• Bart told Zhao Zijie and Gao Yang they had to stay on Titan because the plan had changed.
• Robots built a shallow, insulated steel basin with an electric heater on Titan’s shore.
• Zhao Zijie began the extermination plan as the methane tide rose and ordered the Black Lady Twos to lure the jellyfish.
• Zhao Zijie coordinated the starships as they drew vast swarms of jellyfish toward the basin.
• The jellyfish climbed into the heated basin, where the intense heat killed them, and Gao Yang opened the valve to collect their corpses.

Zhao Zijie and Gao Yang ended humanity’s jellyfish hunt on Titan and departed to rendezvous with the fleet near Jupiter. After the humans left, a group of smaller jellyfish gathered around their abandoned equipment, appearing to perform a ritual and showing signs of consciousness.

• Zhao Zijie granted the final Black Lady Two craft permission to return and crossed off the remaining searched sea regions.
• Zhao Zijie explained to Gao Yang that the Kraken-Mare Sea held most of Titan’s liquid and that any surviving jellyfish population might go extinct.
• Zhao Zijie and the other pilots left Titan aboard a Glutton to rendezvous with Heavenly Court near Jupiter, leaving the Luan Bird and hunting apparatus behind.
• Two Titan day-night cycles later, smaller jellyfish gathered around the abandoned human equipment, danced in a circle, and returned to the sea.

Two months later, the human fleet waited near Jupiter as Venus plunged into the Sun, and Lü Yongchang used the event to assess the danger to Jupiter. Zero's simulation suggested that debris from Earth's future plunge could raise Jupiter's mass enough to give it a 27.96% chance of becoming a brown dwarf.

• The 1,251 Nebula-class starships gathered on Jupiter's far side, with the flagship [Earth] at the fleet's center, while Stingrays continued harvesting helium-3.
• Lü Yongchang ordered the fleet's status checked as Zero counted down to Venus's impact with the Sun.
• Venus fell into the Sun and expelled coronal material, which Zero predicted Jupiter would capture in five years.
• Fang Xu and Cao Liangcai expressed relief that the material would reach Jupiter after the fleet had departed, but Lü Yongchang remained concerned.
• Lü Yongchang asked Zero to simulate Earth's plunge into the Sun and estimate how much Jupiter's mass might increase.
• Zero estimated Jupiter could reach 5.11 to 23.17 times its current mass, with a 27.96% chance of becoming a brown dwarf.

Lü Yongchang discovered that an unknown force had absorbed about 30% of the Sun’s mass and simulated Jupiter becoming a red dwarf alongside the Sun’s white dwarf. Ten days later, a solar wind storm was approaching Jupiter, putting the human fleet in danger.

• Lü Yongchang realized the Sun would eject only about 20% of its original mass, leaving roughly 30% unaccounted for.
• Lü Yongchang concluded that something inside the Sun was absorbing its energy, and warned the researchers that humanity should avoid the unknown civilization responsible.
• Zero simulated Jupiter capturing the Sun’s ejected matter and growing into a red dwarf, forming a binary star system with the Sun’s white dwarf.
• Lü Yongchang learned that the simulated binary system would form in fifty thousand to one hundred thousand years.
• Ten days later, an alert announced that a solar wind storm would reach Jupiter’s orbit in thirty minutes.

As the solar wind storm passed Jupiter, Gao Yang worried that the jellyfish on Titan might still exist and become a threat. Lü Yongchang explained how Titan might fare through the Sun’s helium flash and Jupiter’s transformation, then prepared to leave for the Kuiper Belt once the storm passed.

• Zero detected powerful X-rays from Jupiter’s auroras as the solar wind storm swept past the planet.
• Gao Yang told Zhao Zijie he felt they had left something behind on Titan and wondered whether the jellyfish had developed consciousness.
• Lü Yongchang assured Gao Yang that Saturn’s magnetic field shielded Titan from the solar wind storm, then used a simulation to show Titan surviving the Sun’s helium flash.
• Lü Yongchang explained that Titan’s internal heat could sustain the jellyfish, though Jupiter’s eventual transformation into a red dwarf might threaten them.
• Lü Yongchang ended the simulation and said the crew would head for the Kuiper Belt after the solar wind storm passed.

As the fleet resumed its journey from Jupiter, Lü Yongchang used asteroid encounters to train pilots in manual interception. He then asked Mo Zeyang about photon computer development and learned that it had made little progress, leaving the fleet’s technological advancement stalled.

• The fleet left Jupiter, and [Earth] detected a five-kilometer asteroid on a collision course.
• Lü Yongchang ordered Zhao Zijie to have [Golden Crow] B31 destroy the asteroid with electromagnetic cannons and high-energy lasers.
• Fang Xu praised the pilots’ improved skills, and Lü Yongchang explained that he had disabled Zero’s automatic interception so the crews could train before their eventual fight with the Proxima Centauri Civilization.
• Lü Yongchang summoned Mo Zeyang and asked about photon computer development.
• Mo Zeyang reported that the team had made little progress because photon computers required a new architecture and manufacturing capabilities they lacked.

Lü Yongchang tried to force a photon-computer breakthrough from the system, but his repeated attempts left him unconscious, and he decided humanity should delay the research until after facing the Proxima Centauri Civilization. As the fleet neared the Kuiper Belt and the Sun’s helium flash, he watched Earth’s destruction from afar, then saw an intense flash on the Sun.

• Lü Yongchang reviewed the stalled photon-computer research with Mo Zeyang and went to the technology tree to seek a system hint, but collapsed before he could learn anything.
• Doctor Wen told Lü Yongchang that each episode strained his brain, and he agreed to rest and postpone the photon-computer research until after humanity dealt with the Proxima Centauri Civilization.
• In 2045, with one month remaining before the fleet reached the Kuiper Belt and the Sun’s helium flash erupted, Zero reported that the Sun was nearing Earth’s orbit.
• Lü Yongchang asked Zero whether any later probes still worked, and Zero showed him Earth stripped of its atmosphere and water.
• As Lü Yongchang prepared to close the image, an extremely bright point of light flashed across the Sun’s surface.

Lü Yongchang and the command center identified a gigantic artificial sphere that had absorbed thirty percent of the Sun’s mass and was traveling toward the center of the Milky Way. They concluded it had likely harvested the Sun’s energy, leaving humanity’s civilization devastated by an act that may not have been aimed at them.

• Lü Yongchang ordered Zero to replay the footage and magnify a bright object on the Sun’s surface, revealing a smooth, silvery-white artificial sphere.
• Lü Yongchang asked Zero to track the sphere, and Zero found it traveling toward the center of the Milky Way after vanishing from the footage in two seconds.
• Zero estimated that the sphere was 3,000 kilometers in diameter and had been moving at 0.5 to 0.8 times the speed of light.
• Lü Yongchang concluded that the sphere had absorbed thirty percent of the Sun’s mass and was probably harvesting energy, while Cao Liangcai struggled with the revelation.
• Lü Yongchang accepted that the destruction of humanity’s civilization may have been incidental and quietly repeated, “If I destroy you, what business is it of yours?”

Lü Yongchang concluded that humanity’s destruction of the Solar System was likely a targeted strike, but believed the unknown civilization would not attack again. After retrieving the surviving humans from the Luan Bird starships, the fleet abandoned the Solar System and began its century-long journey to Proxima Centauri.

• Lü Yongchang told the researchers that Voyager may have exposed humanity to an advanced civilization and argued that the attack on the Solar System was targeted.
• A month later, Lü Yongchang led the fleet to the Kuiper Belt, where it found 380 Luan Bird starships carrying 3.8 billion people in hibernation.
• Zero reported that the hibernation chambers were mostly intact and that 16,936 people had died; Lü Yongchang ordered the survivors and useful resources transferred to the fleet.
• Zero told Lü Yongchang that the Sun had undergone a helium flash, and the fleet began evacuating the Luan Bird starships.
• On January 1, 2046, Lü Yongchang entered hibernation aboard the Earth as the fleet accelerated toward Proxima Centauri, with arrival estimated for 2146.

Lü Yongchang was awakened fifty years early after Proxima Centauri triggered a Level-One Anomaly: the star was rapidly dimming, apparently due to an energy-harvesting device like the one that had threatened Earth's Sun. He told the command center that humanity still had to reach Proxima Centauri because the fleet lacked supplies to go elsewhere, then hinted at some good news.

• Zero awakened Lü Yongchang in 2096 and told him that Proxima Centauri had undergone abnormal changes.
• Lü Yongchang reviewed the observations and learned that Proxima Centauri could die in 120 to 150 years and become a black dwarf.
• Lü Yongchang told the command center that Proxima Centauri appeared to contain an advanced civilization's energy-harvesting device and that the situation supported the dark forest law.
• Fang Xu asked whether the fleet would still travel to Proxima Centauri, and Lü Yongchang said it had to because its fuel and replacement parts would only last to the nearest star.
• Lü Yongchang said there was some good news, or one and a half pieces of good news.

Lü Yongchang warned that the Proxima Centauri civilization might be fleeing toward the Solar System as humanity traveled toward Proxima Centauri. Sweeper 9527 discussed the Star Eater's disappointing results and ordered his subordinate to watch for a Gardener Faction creature, while Levi faced an unexpected visit from a Lair.

• Lü Yongchang showed that the Solar System was the nearest likely destination for the Proxima Centauri people, raising the possibility that both civilizations were heading toward each other.
• Sweeper 9527 learned that the Star Eater had absorbed little energy from a yellow dwarf and that the Star Eater near a red dwarf still needed more time.
• Sweeper 9527 dismissed a proposed attack on a distant level three civilization and ordered his subordinate to report any trace of the two-dimensional Gardener Faction creature in the Orion Arm.
• In 2100, Levi oversaw Proxima Centauri people and Marus building escape starships after the rebel uprising succeeded.
• Levi refused to meet a Lair, but the Lair forced his way into the room and insisted he had not come to fight.

Lair told Levi that the Solar System was no longer a viable escape destination because its star had become a white dwarf, and that the news had been delayed for fifty years by the Academy of Sciences. He proposed reducing the number of evacuees by choosing another destination, leaving Levi facing the conflict between his public promise and his plan to prioritize Proxima Centauri people over the Marus.

• Lair told Levi that the Solar System's star had undergone a helium flash fifty years earlier and was turning into a white dwarf.
• Levi demanded to know why the Academy of Sciences had only discovered the change now, and Lair blamed its inefficient handling of documents.
• Lair suggested choosing another destination and reducing the number of evacuees because the ships under construction could not save everyone.
• Levi recalled that he had promised everyone, including the Marus, a place on escape ships, but had secretly realized that only around five hundred thousand people could be evacuated.
• Levi admitted to himself that he planned to give Proxima Centauri people priority over the Marus, and Lair told him they were the same.