However, the anticipated mass hysteria did not occur. Faced with the catastrophe four light-years away, human society became strangely quiet. Everyone seemed to be waiting, but at a loss as to what they were waiting for.

For the first time, humanity witnessed the extinction of a civilization, and realized such a fate might befall Earth at any moment. The threat of Trisolaris, a crisis that had lasted close to three centuries, dissipated overnight, yet what took its place was an even crueler universe.

They were waiting for another miracle.

Ever since the Great Ravine, although history had taken multiple big turns, humanity, as a whole, had always lived in a society that was highly democratic, with ample welfare. For two centuries, the human race had held on to a subconscious consensus: No matter how bad things got, someone would step in to take care of them. This faith had almost collapsed during the disastrous Great Resettlement, but on that darkest of mornings six years ago, a miracle had nonetheless taken place.

The UN and Fleet International were intensely interested in the meeting. The expectant, lost attitude prevalent in society posed a terrible danger. Human society was as fragile as a sand castle on the beach, prone to collapse with a passing gale. The leaders wanted the two former Swordholders to gather some information from Sophon that would reassure the people. In an emergency session of the PDC convened for this purpose, someone even hinted to Cheng Xin and Luo Ji that even if they couldn't get such intelligence from Sophon, perhaps it was acceptable to manufacture some.

After the universal broadcast of six years ago, Sophon had retreated from public life. Once in a while, she might appear in public, but only to serve as an expressionless speaking tube for Trisolaris. She had remained in that elegant dwelling hanging from a tree branch, though most of the time she was probably in standby mode.

On the third day after witnessing the destruction of Trisolaris, Sophon invited Cheng Xin and Luo Ji to tea. She said that she had no ulterior motives. They were old friends, after all, and she missed them.

To Cheng Xin's eyes, Luo Ji appeared to have retained his upright, cold demeanor. Other than the fact that his hair and beard appeared even whiter in the breeze, the past seven years seemed to have left no mark on him. But then, without speaking, he smiled at her, and the gesture made her feel warm. Luo Ji reminded Cheng Xin of Fraisse. Though the two were completely different, they both brought with them some mountainlike strength from the Common Era, and gave Cheng Xin the sense that they could be relied on in this strange new time. Wade, the Common Era man who was as evil and vicious as a wolf and who had almost killed her, also had it -- so she found herself relying even on him. It was an odd feeling.

Cheng Xin met Luo Ji on the bough leading to Sophon's house. Luo Ji had spent the Great Resettlement with the Resistance. Although he did not directly participate or lead any operations, he remained the spiritual center of the resistance fighters. The Earth Security Force and the droplets had made every effort to seek him out and kill him, but somehow, he had managed to evade them. Not even the sophons could locate him.

A complex mix of feelings flooded Cheng Xin's heart as she watched Sophon's graceful movements.

Sophon welcomed them in front of her house. Once again, she was dressed in a splendid kimono, and she wore fresh flowers in her bun. That vicious ninja dressed in camouflage had disappeared completely, and she was once again a woman who resembled a bubbling spring nestled among flowers.

"Welcome, welcome! I wanted to pay a visit to your honored abode, but then I wouldn't be able to properly entertain you with the Way of Tea. Please accept my humble apologies. I am so delighted to see you." Sophon bowed to them, and her words were as gentle and soft as the first time Cheng Xin had met her. She led the two through the bamboo grove in her yard, across the little wooden bridge over the trickling spring, and into the pavilionlike parlor. Then the three sat down on tatami mats, and Sophon began to set out the implements for the Way of Tea. Time passed tranquilly, and clouds rolled and unfurled across the blue sky outside.

Yes, she (or they?) could have succeeded in wiping them out, and had almost succeeded several times. But each time, humanity had snatched victory from the jaws of defeat through tenaciousness, cunning, and luck. After a three-century-long march, all Sophon had managed was to see her home annihilated in a sea of flames.

Sophon had known of the destruction of Trisolaris four years ago. Three days earlier, after the light from the explosion had reached the Earth, she had given a brief speech to the public. She recounted the death of Trisolaris in simple words, and made no denunciation or judgment of the cause -- the gravitational wave broadcast initiated by two human ships. Many suspected that four years ago, when Trisolaris had been wiped out, those who had controlled her from four light-years away had perished in the fiery flames, but her current controllers were more likely on the spaceships of the Trisolaran Fleet. During the speech, Sophon's tone and expression had been calm. This wasn't the same as the woodenness she had shown when she had merely acted as a speaking tube, but a manifestation of her controllers' soul and spirit, a dignity and nobility in the face of annihilation that humanity could not hope to equal. People now felt an unprecedented awe toward this civilization that had lost its home world.

The limited information provided by Sophon and the Earth's own observations drew a rough picture of Trisolaris's destruction.

At the time of the catastrophe, Trisolaris was in a stable era, orbiting around one of the three stars in the system at a distance of about 0.6 AU. The photoid struck the star and tore a hole through the photosphere and the convection zone. The hole was about fifty thousand kilometers in diameter, wide enough for four Earths laid side by side. Whether as a result of a deliberate choice by the attacker or coincidence, the photoid struck the star at a point along the line where the star intersected Trisolaris's ecliptic plane. Viewed from the surface of Trisolaris, an extremely bright spot appeared on the surface of the sun. Like a furnace with its door open, the powerful radiation generated by the core of the sun shot through the hole; passed through the convection zone, the photosphere, and the chromosphere; and struck the planet directly. All life outdoors on the hemisphere exposed to the radiation was burnt to a crisp within a few seconds.

Next, material from the core of the sun erupted from the hole, forming a fifty-thousand-kilometer-thick fiery plume. The spewed material was tens of millions of degrees in temperature, and while some of the material fell back onto the surface of the sun under the influence of gravity, the remainder reached escape velocity and shot into space. Viewed from Trisolaris, a brilliant tree of fire grew from the surface of the sun. About four hours later, the ejected solar material reached 0.6 AU from the surface of the sun, and the tip of the flaming tree intersected the orbit of Trisolaris. After another two hours, the orbiting planet reached the tip of the fire tree and continued to pass through the ejected solar material for about thirty minutes. During this time, the planet might as well be moving through the interior of the sun -- even after the journey through space, the spewed material was still at a blazing temperature of tens of thousands of degrees. By the time Trisolaris emerged from the fire tree, it glowed with a dim red light. The entire surface had liquefied, and an ocean of lava covered the planet. Behind the planet was a long white trail through space -- steam from the boiled-off ocean. The solar wind stretched the trail out, making the planet appear as a long-tailed comet.

The ejected solar material caused drag against the planet. After passing through the material, Trisolaris slowed down, and its orbit fell lower toward the star. The fire tree acted like a claw extended from the sun, pulling Trisolaris down with each revolution. After about ten more revolutions, Trisolaris would fall into the sun itself, and the cosmic football game played between three suns would come to its end. But this sun wouldn't survive long enough to see itself emerge as the victor.

All signs of life on Trisolaris had been cleansed away, but only the fuse of the catastrophe had been lit.

The solar eruption also lowered the pressure inside the sun, temporarily slowing down the fusion within the core. The sun dimmed rapidly until it was but a hazy outline. The giant fiery tree growing from the surface, in contrast, appeared even more striking, more brilliant, like a sharp scratch made against the inky black film of the universe. The diminished fusion meant that the core radiation no longer exerted sufficient pressure against the weight of the solar shell, and the sun began to collapse. The dim shell fell into the core, triggering a final explosion.

The solar explosion destroyed everything within the planetary system: The vast majority of spaceships and space habitats trying to escape were vaporized. Only a few extremely fortunate ships that happened to be behind the two other suns, which acted as shields, were safe.

This was the sight witnessed by humankind three days ago on Earth.

Cheng Xin had much more to say, words from one woman to another, but she was a member of the human race, and the chasm that now divided her from Sophon could not be crossed. She resorted to the questions the leaders had wanted her to ask. The conversation that followed would come to be known as the Conversation of the Way of Tea, which would profoundly change the subsequent progress of history.

Thereafter, the remaining two suns formed a stable double-star system, but no life would witness the regular sunrises and sunsets. The cinders of the exploded star and the incinerated Trisolaris formed two vast accretion discs around the two suns, like two gray graveyards.

"How many escaped?" Cheng Xin asked softly.

"Counting the Trisolaran Fleets far from home, no more than one-thousandth of the entire population." Sophon's reply was even softer than Cheng Xin's query. She was focused on the Way of Tea, and did not raise her head.

"How much longer do we have?" Cheng Xin asked.

"We can't tell. The attack could come at any moment. But probabilistically, you should have a bit more time: maybe as long as one to two centuries, like your last experiment." Sophon glanced at Luo Ji and then sat up straight, her face expressionless.

Sophon shook her head determinedly. "We can never explain this to you."

Cheng Xin looked at Luo Ji in shock, but the latter showed no reaction. She asked, "Why?"

"But --"

"Trisolaris was in a different situation from the Solar System. First, the broadcast only included the coordinates of Trisolaris. To discover the existence of Earth based on this requires examining the record of communications between the two worlds from three centuries ago. That will definitely happen, but it will take time. More important, from a distance, the Trisolaran system appears far more dangerous than the Solar System."

Cheng Xin returned to the planned questions. "The two attacks we've seen both used photoids striking the stars. Is this a common attack method? Will the future attack on the Solar System be similar?"

"Any possible defenses?"

"These attacks are not part of some interstellar war, but a matter of conveniently eliminating possible threats. By 'casual,' what I mean is that the only basis for the attack is the exposure of the target's location. There will be no reconnaissance or exploration conducted against the target beforehand. For a supercivilization, such exploration is more expensive than a blind strike. By 'economical,' what I mean is that the attack will employ the least expensive method: using a small, worthless projectile to trigger the destructive potential already present in the target star system."

"Elaborate, please."

"The energy within the stars."

"Dark forest attacks all share two qualities: one, they're casual; two, they're economical."

Sophon nodded. "That is what we've seen so far."

Sophon smiled and shook her head. She spoke patiently, as though to a naïve child. "The whole universe is in darkness, but we remain lit. We're a tiny bird tied to a branch in the dark forest, with a spotlight trained on us. The attack could come from any direction, at any time."

"Become refugees among the stars? But we cannot manage to get even one-thousandth of our population away."

"Please believe me. Humankind has no chance of surviving a strike. Your only choice is to try to escape."

"But based on the two attacks we've seen, there may be a way to engage in passive defenses. Even some Trisolaran ships survived in the home star system behind the other suns."

"That's still better than complete annihilation."

Not by our values, Cheng Xin thought, though she said nothing.

"Let's talk no more of this. Please don't ask more questions. I've told you everything I can. I asked my friends here for tea." Sophon bowed to the two, and then presented two bowls of green tea.

Luo Ji, who had said nothing so far, seemed relaxed. He appeared familiar with the Way of Tea, and holding up his bowl in the palm of his left hand, he rotated it three times with his right hand before taking a drink. He drank slowly, letting time pass in silence, not finishing until the clouds outside the window were colored a golden yellow by the setting sun. He set down the bowl slowly, and said his first words. "May I ask some questions, then?"

Cheng Xin had many more questions on her list. She was anxious as she accepted the tea, but she knew that asking more questions would be useless.

In response to Luo Ji's question, Sophon bowed again. "Please wait." She lowered her eyes and sat still, as though deep in thought. Cheng Xin knew that several light-years away, on the ships of the Trisolaran Fleet, Sophon's controllers were engaged in an urgent debate. About two minutes later, she opened her eyes. "Honored Luo Ji, you may ask one question. I can only affirm, deny, or tell you I don't know."

Luo Ji's respect among the Trisolarans had been shown through Sophon's attitude. Cheng Xin noticed right away that while Sophon was gentle and friendly with her, she was awed by Luo Ji. Whenever she faced Luo Ji, her eyes revealed her feelings, and she always sat farther away from Luo Ji than Cheng Xin, and bowed to him slower and deeper.

Luo Ji set down the tea bowl again. But Sophon raised her hand, asking him to wait. "This is a gesture of respect from our world to you. My answer will be true, even if the answer could cause harm to Trisolarans. But you have only one question, and my answer must be from those three choices. Please consider it carefully before you speak."

Cheng Xin gazed at Luo Ji anxiously, but the latter didn't pause at all. In a decisive tone, he said, "I've considered it. Here's my question: If Trisolaris showed certain signs of being dangerous when observed from a distance, does there exist some sign that can be shown to the universe to indicate that a civilization is harmless and will not threaten anyone else, thus avoiding a dark forest strike? Can Earth civilization broadcast such a 'safety notice,' if you will, to the universe?"

Sophon did not answer for a long time. Again, she sat still, pondering with her eyes lowered. Cheng Xin felt time flow more slowly than ever. With every passing second, her hope diminished, and she was certain that Sophon's answer was going to be no or I don't know. But abruptly, Sophon looked up at Luo Ji with clear eyes -- before then, she had never even dared to meet his gaze directly -- and answered without any doubt: "Yes."

"How?" Cheng Xin couldn't help herself.

Sophon looked away from Luo Ji, shook her head, and refilled their tea bowls. "I can tell you nothing more. Really. I can never tell you anything again."

[Excerpt from A Past Outside of Time, The Cosmic Safety Notice: A Lonely Performance Art]

After the conversation between Sophon, Cheng Xin, and Luo Ji was publicized, everyone began to ponder the problem of how to broadcast a safety notice. Countless proposals flooded in, sent by sources as august as the World Academy of Sciences and as humble as elementary schools. It was perhaps the first time in the history of humanity that the entire species focused their mental energy on the same practical problem.

The Conversation of the Way of Tea gave the tiniest bit of hope for the expectant mass of humanity: It was possible to broadcast a safety notice to the cosmos to avoid dark forest strikes.

All the proposals could be divided into two broad categories: the declaratory camp and the self-mutilation camp.

The more they thought about it, the more the safety notice turned into a riddle.

The declaratory camp's basic conception, as can be intuited from the name, was a broadcast to the universe proclaiming the harmlessness of Earth civilization. Their main efforts were directed at how to express such a message. But in the eyes of most, their premise seemed foolish. No matter how well crafted the message, who in this heartless universe would believe it? The fundamental requirement for a safety notice was that the countless civilizations in the universe would trust it.

The self-mutilation camp represented the majority view. They theorized that the safety notice had to represent the truth, which implied that the notice required both "talking" and "doing." And of the two, "doing" was the key. Humanity had to pay a price for living in the dark forest and transform Earth civilization into a truly safe civilization -- in other words, Earth civilization had to mutilate itself to eliminate its potential to threaten others.

More extreme ideas emerging from the self-mutilation camp proposed intellectual disablement. Using drugs or other neuromanipulation techniques, humans could lower their own intelligence. Moreover, such lowered intelligence could be fixed via genetic manipulation in future generations. As a result, a low-technology society would result naturally. Most people were revolted by the notion, but it remained in wide circulation. According to the proponents, the safety notice was equivalent to public disclosure of humanity's low intelligence.

Most of the self-mutilation plans focused on technology and advocated humanity to retreat from the space age and the information age and found a low-technology society -- perhaps a society reliant on electricity and the internal combustion engine, such as at the end of the nineteenth century, or even an agrarian society. Considering the rapid decline in global population, these plans were feasible. In that case, the safety notice would be nothing more than an announcement that the Earth possessed a low level of technology.

But none of these plans captured the essence of the safety notice.

There were other ideas as well. For instance, the self-deterrence camp advocated building a system that, once activated, would be beyond human control. The system would monitor humanity for any behavior incongruent with its self-proclaimed safe nature and initiate the destruction of the world upon detection.

As Sophon pointed out, a key characteristic of dark forest strikes was their casual nature. The attacker did not bother to conduct close-range surveillance of the target. All these plans engaged in performance art with no audience. No matter how faithful the act, no one would see it except the performer. Even under the most optimistic conditions -- suppose some civilizations, like doting parents, cared to observe Earth civilization up close, perhaps even devoting long-term monitoring equipment to the Solar System similar to the sophons, they would still make up only a minuscule portion of the large number of civilizations in the universe. In the eyes of the vast majority of civilizations, the sun was but a dim dot many, many light-years away, showing no distinguishing details at all. This was the fundamental mathematical reality of the cosmic dark forest.

This was a feast for the imagination. Countless plans competed for attention: some subtle, some strange, yet others as sinister and terrifying as cults.

Once, when humankind had been far more naïve, some scientists had believed that it was possible to detect the presence of distant civilizations by astronomical observation: for instance, the absorption spectral signatures of oxygen, carbon dioxide, and water vapor in exoplanetary atmospheres, or electromagnetic emissions. They even came up with whimsical notions like searching for signs of Dyson spheres. But we found ourselves in a universe in which every civilization endeavored to hide itself. If no signs of intelligence could be detected in a solar system from far away, it was possible that it really was desolate, but it was also possible that the civilization there had truly matured.

A safety notice was in reality a universal broadcast as well, and it had to ensure that all listeners would trust its message.

Take a distant star, a barely visible dot. Anyone casually glancing at it would say: Oh, that star is safe; that star will not threaten us. That was what a cosmic safety notice had to accomplish.

Utterly impossible.

Another mystery that no one seemed able to solve: Why wouldn't Sophon tell humanity how to broadcast such a safety notice?

It was understandable that the survivors of Trisolaran civilization would no longer transfer technology to humanity. After the gravitational wave broadcast, both worlds faced enmity from the entire galaxy, even the entire universe. They were no longer each other's greatest threats, and the Trisolarans had no time to spare for the Earth. As the Trisolaran Fleet sailed farther away, the connection between the two civilizations grew ever more tenuous. But there was one fact that neither Trisolarans nor humankind could forget: Everything that had happened started with Trisolaris. They were the ones who had initiated the invasion of the Solar System; who had attempted, but failed, to commit genocide. If the Earth managed to make great leaps in technology, revenge was inevitable. Humans were likely to come after whatever new home the surviving Trisolarans found among the stars, and they might complete their revenge before the Earth was destroyed in a dark forest strike.

A European NGO tried to build an extremely powerful antenna that would take advantage of the Sun's amplification ability to broadcast their draft version of such a notice. The police stopped them in time. The six droplets in the Solar System had left six years ago, and there were no more blocks on the Sun's amplification function, but such a transmission would have been extremely dangerous and exposed the Earth's location even sooner.

But a safety notice was different: If such a notice could make the whole universe believe the Earth was harmless, then, by definition, the Earth would be harmless toward the Trisolarans. Wasn't this just what they wanted?

Although there were no clues for how to send out a true safety notice, and any serious research only confirmed the impossibility of such an endeavor, the public's yearning for the notice could not be stopped. Although most people understood that none of the existing proposals would work, attempts to implement them never ceased.

[Broadcast Era, Year 7, Sophon]

Another organization named Green Saviors had several million members. They advocated humanity's return to an agrarian existence, thereby proclaiming their safety to the universe. About twenty thousand of their members moved to Australia. On this sparsely populated continent where the Great Resettlement was but a memory, they planned to create a model society. The agrarian lives of these Green Saviors were continuously broadcast to the rest of the world. In this age, it was no longer possible to find traditional farming implements, and so the tools they used had to be custom-made with funds from their sponsors. There wasn't much arable land in Australia, and all of it was devoted to high-end, expensive foods, and so the settlers had to open up new land in desolate areas designated by the government.

It took only one week before these pioneers stopped collective farming. It wasn't because the Green Saviors were lazy -- their enthusiasm alone could have sustained them through some period of diligence -- rather, it was because the bodies of modern humans had changed considerably from the past. They were more flexible and agile compared to past generations, but were no longer adapted to boring, repetitious physical labor. And opening up wastelands, even in agrarian times, was an extremely physically demanding task. After the leaders of the Green Saviors suitably expressed their respect for their farming ancestors, the movement dissolved, and the idea of a model agrarian society was abandoned.

Faced with the omnipresent threat of death and the lure of a different state of existence, religion once again took center stage in social life.

Historically, the discovery of the dark forest state of the universe was a giant blow to most major religions, especially Christianity. In fact, the damage to religion was evident even early on during the Crisis Era. When Trisolaran civilization was discovered, Christians had to wrestle with the fact that the aliens were not in the Garden of Eden, and God never mentioned them in Genesis. For more than a century, churches and theologians struggled to complete a new interpretation of the Bible and of accepted doctrines -- and just when they had almost succeeded in patching up the faith, the monster that was the dark forest appeared. People had to accept the knowledge that many, many intelligent civilizations existed in the universe, and if each civilization had an Adam and an Eve, then the population of Eden must have been about the same as the current population of Earth.

Perverted ideas about the safety notice also led to vicious acts of terrorism. Some "anti-intellect" organizations were formed to put into practice the proposal to lower human intelligence. One of these planned to add large quantities of "neural suppressors" to the water supply of New York City, which would have caused permanent brain damage. Fortunately, the plot was uncovered in time and no harm was done, though NYC's water supply was out of commission for a few hours. Of course, without exception, these "anti-intellect" organizations wanted to maintain the intelligence of their own members, arguing that they had the responsibility to be the last of the intelligent people so that they could complete the creation of a society of low-intelligence humans and direct its operation.

But during the disastrous Great Resettlement, religions revived themselves. A new belief now became popular: In the past seventy years, humanity twice came to the brink of utter annihilation, but each time, they escaped miraculously. The two miracles, the creation of dark forest deterrence and the initiation of the universal gravitational wave broadcast, shared many characteristics: They both happened under the direction of a small number of individuals; their occurrence depended on a series of improbable coincidences (such as the fact that Gravity, Blue Space, and the droplets all entered the four-dimensional fragment simultaneously)… All these were clearly signs from some deity. At the time of both crises, the faithful had engaged in mass prayer sessions in public. It was precisely such fervent demonstrations of faith that finally led to divine salvation -- though just which god was responsible was a topic of endless debate.

And so the Earth turned into a giant church, a planet of prayer. Everyone prayed with unprecedented faith for another act of salvation. The Vatican led numerous globe-wide Masses, and people prayed everywhere in small groups or individually. Before meals and sleep, they all prayed for the same thing: Lord, please give us a hint; guide us to express our goodwill to the stars; let the cosmos know that we're harmless.

Even Trisolaran civilization became the object of worship. Historically, Trisolaran civilization's image changed continuously in the eyes of humankind. At the beginning of the Crisis Era, they were powerful, evil alien invaders, but were also deified by the ETO. Later, Trisolaris gradually changed from devils and gods to people. With the creation of dark forest deterrence, Trisolaris's position in the eyes of humanity reached its nadir, and Trisolarans became uncivilized savages living at the pleasure of humankind. After deterrence failed, the Trisolarans revealed themselves to be genocidal conquerors. However, after the universal broadcast was initiated -- and especially after the destruction of Trisolaris -- Trisolarans turned into victims who deserved sympathy from humans, fellow refugees in the same boat.

A cosmopolitan space church was built in near-Earth orbit. Though it was called a church, there was no physical building other than a gigantic cross. The two beams making up the cross were twenty kilometers and forty kilometers long, respectively, and glowed so bright that the cross was visible from the Earth at night. The faithful would drift below it in space suits in worship, and as many as tens of thousands sometimes participated. Drifting along with them were countless giant candles capable of burning in vacuum, and the candles competed with the stars in brilliance. Viewed from the surface, the candles and the worshipping congregation seemed like a cloud of glowing space dust. And each night, innumerable individuals on the surface prayed to the cross among the stars.

After finding out about the concept of a safety notice, humans initially reacted to the news unanimously: a vociferous demand that Sophon divulge the method to broadcast a safety notice accompanied by the warning that she not commit mundicide by withholding such information. Yet soon people realized that rage and denunciations were useless against a civilization that had mastered technology far beyond humanity's knowledge and was moving farther and farther away in interstellar space. It would be far better to ask nicely, which then turned into begging. Gradually, as humans begged and begged in a cultural environment of waxing religiosity, the image of the Trisolarans transformed again. Since they possessed the secret of broadcasting the safety notice, they were angels of salvation sent by God. The only reason that humanity had not yet received such salvation was due to insufficient expression of their faith. And so the pleas directed at Sophon turned into prayers, and the Trisolarans once again became gods. Sophon's abode became a holy place, and every day, large numbers of the faithful gathered below the giant tree. At its peak, the congregation was a group several times larger than that of pilgrims in Mecca, forming an endless sea. Sophon's house hung in the air about four hundred meters above the crowd. From the surface it appeared tiny, hidden from time to time by the cloud it generated. Occasionally, Sophon would appear -- the crowd couldn't see any details, but they could see her kimono as a tiny flower in the cloud. These moments were few and far between, and they became sacred. Adherents of every faith in the crowd expressed their piety in various ways: some prayed more fervently, some cheered, some cried and poured out their hearts, some knelt, some threw themselves down and touched their foreheads to the ground. On these occasions, Sophon bowed slightly to the mass of humanity below and then quietly retreated into her house.

Like a moody child, human society's attitude toward Blue Space, which had already vanished in the depths of space, transformed again. From an angel of salvation, this ship again turned into a ship of darkness, a ship of devils. It had hijacked Gravity and cast a sinful spell of destruction on two worlds. Its crimes were unforgivable. It was Satan in the flesh. Sophon's worshippers also pleaded for the Trisolaran Fleet to find and destroy the two ships, to safeguard justice and the dignity of the Lord. As with their other prayers, Sophon did not respond.

There were still many sensible people like him pursuing in-depth research on the safety notice in all areas of study. The explorers worked tirelessly, trying to find a method built on a solid scientific foundation. But all avenues of research seemed to lead to one inescapable conclusion: If there really were a way to release a safety notice, it would require a brand-new kind of technology. The technology must far exceed the current level of science on Earth and was unknown to humankind.

"Even if salvation were to arrive now, it would be meaningless," said Bi Yunfeng. "We have no shred of dignity left." He had once been one of the candidates for the Swordholder position, as well as the commander of the Earth Resistance Movement's branch in Asia.

Simultaneously, Cheng Xin's image in the public consciousness slowly changed as well. She was no longer a Swordholder unqualified for the position; she was again a great woman. People dug up an ancient story, Ivan Turgenev's "Threshold," and used it to describe her. Like the young Russian girl in that story, Cheng Xin had stepped over the threshold that no others dared to approach. Then, at the crucial moment, she had shouldered an unimaginable burden and accepted the endless humiliation that would be her lot in the days to come by refusing to send out the signal of death to the cosmos. People did not linger on the consequences of her failure to deter; instead, they focused on her love for humanity, the love that had caused so much pain that she had gone blind.

At a deeper level, the public's feeling for Cheng Xin was a reaction to her subconscious maternal love. In this family-less age, mother's love was a rare thing. The welfare state that seemed like heaven satiated the children's need for the love of a mother. But now, humanity was exposed to the cruel, cold universe, where Death's scythe may fall at a moment's notice. The baby that was human civilization had been abandoned in a sinister, terrifying dark forest; it cried, hoping for a mother's touch. Cheng Xin was the perfect target for this yearning, mother's love incarnate. As the public's feelings for Cheng Xin gradually melded with the thickening atmosphere of religiosity, her image as the Saint Mary of a new era once again gained prominence.

Life had long ago become a burden and torture for Cheng Xin. She had chosen to remain alive because she didn't want to avoid what she needed to bear -- her continued existence was the fairest punishment for her great error, and she accepted it. But now, she had turned into a dangerous cultural symbol. The growing cult centered on her was adding to the fog that already trapped a lost humanity. To vanish forever would be her last act of responsibility.

For Cheng Xin, this cut off the last of her will to live.

Cheng Xin found the decision to be easy -- effortless, really. She was like someone who had long ago planned to go on a long journey: finally, she had been relieved of her daily grind, and she was ready to pack lightly and set off.

She took out a tiny bottle: the medication for short-term hibernation. There was only one capsule left inside. It was the same drug she had used to hibernate for six years, but without an external cardiopulmonary bypass system to maintain life, it was fatal.

Cheng Xin's mind was as transparent and empty as space: there was no memory, no sensation. The surface of her consciousness was smooth as a mirror, the setting sun of her life reflected in it, as natural as any dusk… It was right and proper. If a world could turn to dust in the snap of a finger, then the end of a person's life should be as placid and indifferent as a dewdrop rolling off the end of a blade of grass.

Just as Cheng Xin picked up the capsule in her hand, her phone rang. It was Fraisse.

"Child, everything is going to get better." Fraisse hung up.

He shouldn't have noticed anything different. Their conversations were all this brief.

Fraisse never used the video function of his phone, as though he thought his words would be more vivid than any image. Although she knew he couldn't see her, Cheng Xin smiled. "That's wonderful, Fraisse. Thank you."

艾 AA had come that morning as well, excitedly telling Cheng Xin that her company had won the bid on another large project: building an even bigger cross in geosynchronous orbit.

"Child, the moon is very lovely tonight. I just saw a kangaroo. I guess the refugees hadn't eaten them all."

Cheng Xin realized that she still had two friends. In this brief, nightmarish period of history, she had only these two real friends. If she ended her life now, how would they feel? Her transparent, empty heart tightened and cramped up, as though squeezed by numerous hands. The placid surface of the lake in her mind shattered, and the reflected sunlight burned like fire. Seven years ago, she hadn't been able to press that red button in front of all of humanity; now, thinking of her two friends, she could not swallow this capsule that would bring her relief. She saw again her boundless weakness. She was nothing.

Slowly, Cheng Xin put the capsule back in the bottle. She would make this appointment. This meant she had enough time to wade across the river of pain.

The phone rang again. It was Sophon. She invited Cheng Xin and Luo Ji to tea again. She was going to tell them good-bye for the last time.

The next morning, Cheng Xin and Luo Ji returned to Sophon's aerial abode. They saw a gigantic crowd gathered a few hundred meters below it. Sophon had announced to the world last night that she was going to leave, and the crowd of worshippers was several times larger than typical. Instead of the usual prayers and pleas, the congregation was silent, as though waiting for something.

A moment ago, the river in front of her had been frozen solid, and she could have easily walked to the other shore. But now, the surface had melted, and she would have to wade through the black, icy water. This was going to be a long process of torture, but she trusted herself to walk to the other shore. Perhaps she would hesitate and struggle until the next morning, but she would swallow that capsule in the end. She had no other choice.

Sophon presented a bowl of tea to Luo Ji with both hands. "I'm leaving. I hope the two of you will take care and be well." Then she presented Cheng Xin with her bowl. "The universe is grand, but life is grander. Perhaps fate will direct us to meet again."

This time, the Way of Tea was conducted in silence. They all knew that everything that needed to be said between the two worlds had already been said.

In front of the door to her house, Sophon welcomed them the same way.

Cheng Xin and Luo Ji could both feel the presence of the people below. The expectant crowd was like a giant noise-absorbing carpet that deepened the silence in the parlor. It was almost oppressive, as if the clouds outside the window had grown more solid. But Sophon's movements remained gentle and graceful, making no noise even when the implements came in contact with porcelain. Sophon seemed to be using her grace and elegance to counteract the heavy air. More than an hour passed, but Cheng Xin and Luo Ji did not feel the flow of time.

Cheng Xin sipped the tea quietly. She closed her eyes to concentrate on the taste. The clear bitterness seemed to suffuse her body, as though she had drunk cold starlight. She drank slowly, but finally, she was done.

Cheng Xin and Luo Ji got up to say farewell for the last time. Sophon accompanied them all the way up onto the branch. They saw that the white clouds generated by Sophon's house had disappeared for the first time in memory. Below them, the sea of expectant people still waited in silence.

"Before we say good-bye, I'm going to finish my last mission. It's a message." Sophon bowed deeply to both of them. Then she straightened up and looked at Cheng Xin.

"Yun Tianming would like to see you."

[Excerpt from A Past Outside of Time, The Long Staircase]

Near the beginning of the Crisis Era, before the Great Ravine had extinguished humanity's enthusiasm, the nations of the Earth had banded together and accomplished a series of great deeds for the defense of the Solar System. These gigantic engineering projects had all reached or breached the limits of the most advanced technology of the time. Some of them, such as the space elevator, the test of the stellar-class nuclear bombs on Mercury, the breakthroughs in controlled nuclear fusion, and so on, had been recorded by history. These projects built a solid foundation for the technological leap after the Great Ravine.

But the Staircase Project wasn't one of them; it had been forgotten even before the Great Ravine. In the eyes of historians, the Staircase Project was a typical result of the ill-thought-out impulsiveness that marked the beginning of the Crisis Era, a hastily conducted, poorly planned adventure. In addition to the complete failure to accomplish its objectives, it left nothing of technological value. The space technology that eventually developed took a completely different direction.

No one could have predicted that nearly three centuries later, the Staircase Project would bring a ray of hope to an Earth mired in despair.

It would probably forever remain a mystery how the Trisolarans managed to intercept and capture the probe carrying Yun Tianming's brain.

One of the cables holding the sail to the Staircase probe had broken near the orbit of Jupiter. The craft had deviated from its planned path, and the Earth, deprived of its flight parameters, lost it to the endless depths of space. If the Trisolarans had been able to intercept it later, they must have had its flight parameters after the cable broke; otherwise, even the advanced Trisolaran technology would have been incapable of locating such a small object in the vastness of space outside the Solar System. The most likely explanation was that the sophons had followed the Staircase Project probe, at least through its acceleration leg, to gather its final flight parameters. But it seemed unlikely that the sophons had followed the craft for the remainder of its long journey. The craft had passed through the Kuiper Belt and the Oort Cloud. In these regions, it could have decelerated or been pushed off course by interstellar dust. It appeared that none of these things happened, because Trisolarans wouldn't have been able to get updated parameters. Thus, the successful interception of the probe required some measure of luck.

It was virtually certain that a ship from the First Trisolaran Fleet was responsible for capturing the probe -- most likely the one ship that had never decelerated. At the time, it had been sent way ahead of the rest of the fleet so that it could arrive in the Solar System a century and a half before the other ships -- but, due to its extremely high velocity, it couldn't have decelerated in time, and would have had to pass straight through the Solar System. The goal of this ship was still a mystery. After the creation of dark forest deterrence, this ship, along with the rest of the First Trisolaran Fleet, had turned away from the Solar System. The Earth had never ascertained its precise flight parameters, but if it had turned in the same general direction as the rest of the First Fleet, then it was possible that it encountered the Staircase probe. Of course, even so, the two crafts were still at great distances from each other; without precise parameters for the probe's trajectory, the Trisolaran ship couldn't have located it.

A rough estimate -- the only estimate possible given the lack of more information -- would place the moment of interception between thirty and fifty years ago, but not before the Deterrence Era.

Yun Tianming was now aboard the First Trisolaran Fleet. Most of the ships in the fleet were headed in the direction of Sirius. His exact condition was unknown: Perhaps his brain was kept alive by itself; or perhaps it had been implanted in a cloned body. But people were far more interested in a different question:

It was understandable that the Trisolaran Fleet would attempt to capture the Staircase probe. Until the very end, direct contact between the Trisolarans and humans was limited to the droplets. They would have been interested in a live human specimen.

Was Yun Tianming still working for the interests of humanity?

This was a reasonable worry. The fact that Yun Tianming's request to see Cheng Xin had been approved showed that he had already integrated into Trisolaran society, and perhaps even possessed some social status there.

Still, Yun Tianming had appeared at the exact moment when Earth civilization seemed to be bereft of hope. When the news became public, people's first reaction was that their prayers had been answered: The angel of salvation had finally arrived.

The next question was even more troubling: Had he participated in recent history? Did the events of the past century between the two worlds have anything to do with him?