"If I hadn't gone on like that, would you have understood the import of that call? Also, if that were all, I wouldn't have come here. I'm lazy, remember? But there was another thing: It was the middle of the night-I don't know if it was today or yesterday-and I was in bed. As I was drifting halfway between sleep and wakefulness, I felt something cold moving on my face. I opened my eyes and saw Shen Yufei, and I almost died of fright."

"What's so frightening about seeing your wife in the middle of the night?"

"She stared at me in a way that I had never seen. The light from outside fell on her face, and she looked like a ghost. She held something in her hand: a gun! Moving the barrel over my face, she told me that I had to continue working on the three-body problem. Otherwise she'd kill me."

"Oh, now this is getting interesting." Da Shi gave a satisfied nod. He lit another cigarette.

"Interesting? Look, I've nowhere to go. That's why I came to you."

"Tell us exactly what she said."

"She said: 'If you succeed in solving the three-body problem, you will be the savior of the world. If you stop now, you'll be a sinner. If someone were to save or destroy the human race, then your possible contribution or sin would be exactly twice as much as his.'"

Da Shi blew out a thick cloud of smoke and stared at Wei Cheng until he squirmed. He pulled a notepad out of the mess on his desk and picked up a pen. "You wanted us to take notes, right? Repeat what you just said."

Wei did.

w.a.n.g said, "What she said is indeed strange. What does she mean by exactly twice as much?"

Wei blinked. "This seems pretty serious. When I came, the officer on duty immediately sent me to see you. It looks like you've already been paying attention to Shen and me."

Da Shi nodded. "Let me ask you something else: Do you think the gun your wife held was real?" He saw that Wei didn't know how to answer. "Could you smell gun oil?"

"Yes, there was definitely an oily smell."

"Good." Da Shi, who had been sitting on his desk, jumped off. "Finally we have an opening. Suspected illegal possession of firearms is enough to justify a search. I'll leave the paperwork until tomorrow, because we have to move right away."

He turned to w.a.n.g. "No rest for the weary. I have to ask you to come and advise me some more." Then he turned to Xu Bingbing, who'd been silent the whole time. "Bingbing, right now I have only two men on duty, and that's not enough. I know the Information Security Division isn't used to fieldwork, but I need you to come along."

Xu nodded, glad to leave the smoke-filled office.

In addition to Da Shi and Xu, the team for conducting the search consisted of w.a.n.g Miao, Wei Cheng, and two other officers from the Criminal Division. The six of them rode through the predawn darkness in two police cars, heading toward Wei's neighborhood at the edge of the city.

Xu and w.a.n.g were in the backseat. As soon as the car started, she whispered to w.a.n.g, "Professor w.a.n.g, your reputation in Three Body is very high."

Somebody mentioned Three Body in the real world! w.a.n.g was excited, right away feeling close to this young woman in a police uniform. "Do you play?"

"I'm responsible for monitoring and tracking it. An unpleasant task."

w.a.n.g anxiously asked, "Can you tell me its background? I really want to know."

In the faint light coming through the car window, w.a.n.g saw Xu give a mysterious smile. "We want to know as well. But all its servers are outside the country. The system and firewall are very secure and hard to penetrate. We don't know much, but we can be sure it's not operated for profit. The software quality is uncommonly high, and the amount of information contained in it even more unusual. It doesn't even seem like a game."

"Have there been any..." w.a.n.g carefully picked the right words. "... supernatural signs?" w.a.n.g's night had been filled with coincidences: He had been called in to discuss the three-body problem with Wei Cheng immediately after he solved the Three Body game. And now Xu was telling him she was monitoring the game. Something didn't seem right.

"We don't think so. Many from all around the world partic.i.p.ate in the game's development. Their collaboration method seems similar to popular open-source practices, like the kind used to make the Linux operating system. But they're definitely using some very advanced development tools. As for the content of the game, who knows where they're getting it? It does seem a bit ... supernatural, like you said. However, we still believe in Captain Shi's famous rule: All this must be the work of people. Our tracking efforts are effective, and we'll have results soon."

The young woman was not experienced in lying, and her last remark made w.a.n.g realize that she was hiding much of the truth from him. "His 'rule' is famous now?" w.a.n.g looked at Da Shi, who was in the driver's seat.

When they reached the house, the sun had not yet risen. It was about the same time of night that w.a.n.g had seen Shen playing Three Body. A second-story window was lit, but all the other windows were dark.

As soon as w.a.n.g got out of the car, he heard noises coming from upstairs. It sounded like something was slapping against the wall. Da Shi, who had just gotten out of the car himself, immediately became alert. He kicked open the yard gate and rushed into the house with an agility surprising for his burly frame, his three colleagues close behind.

w.a.n.g and Wei followed them into the house. They went upstairs and entered the room with a light on, their shoes splashing in a pool of blood. Shen lay in the middle of the room, blood still oozing from two bullet wounds in her chest. A third bullet had gone through her left brow, causing her whole face to be covered in red. Not far from her, a gun lay in a crimson pool.

As w.a.n.g entered, Da Shi and one of the other officers rushed out and entered the dark room across the hall. The window there was open, and w.a.n.g heard the sound of a car starting outside. A male police officer began to make a phone call. Xu Bingbing stood a little ways apart, watching anxiously. She, like w.a.n.g and the others, had probably never seen a scene like this.

A moment later, Da Shi returned. He put his gun back in its holster and said to the officer holding the phone, "A black Volkswagen Santana with only one man. I couldn't get the license plate number. Tell them to block all entrances to the fifth ring road. s.h.i.t. He might actually get away."

Da Shi looked around and saw the bullet holes in the wall. He glanced at the sh.e.l.l casings scattered on the ground and added, "The man got off five shots, and three hit her. She shot twice-both misses." Then he crouched down to examine the body with the other officer. Xu stood farther away, stealing a glance at Wei Cheng next to her. Da Shi also looked up at him.

On Wei's face was a trace of shock and a trace of sorrow, but only a trace. His usual wooden expression didn't break. He was far calmer than w.a.n.g.

"You don't seem bothered by this," Da Shi said to Wei. "They probably came to kill you."

Wei gave a ghastly grin. "What can I do? Even now, I still don't know anything about her. I've told her many times to keep life simple. I'm thinking of the abbot's counsel to me that night. But ... eh."

Da Shi stood up and walked over to stand in front of Wei. He took out a cigarette and lit it. "I think you still have some things you haven't told us."

"Some things I was too lazy to talk about."

"Then you'd better work harder now!"

Wei thought for a moment and said, "Today-no, yesterday afternoon-she argued with a man in the living room. It's that Pan Han, the famous environmentalist. They had argued a few times before, in j.a.panese, as though afraid to have me listen in. But yesterday they didn't care at all and argued in Chinese. I overheard a few s.n.a.t.c.hes."

"Try to tell us exactly what you heard."

"Fine. Pan Han said, 'Although we seem like fellow travelers on the surface, in reality we're irreconcilable enemies.' Shen said, 'Yes, you're trying to use our Lord's power against the human race.' Pan said, 'Your understanding is not completely unreasonable. We want our Lord to come to this world, to punish those who have long deserved it. However, you're working to prevent our Lord's coming, and that's why we can't tolerate you. If you don't stop, we'll make you stop!' Shen said, 'The commander was blind to allow you to join the organization!' Pan said, 'Speaking of, can you tell whether the commander sides with the Adventists or the Redemptionists? Does the commander want humanity eliminated or saved?' Pan's words briefly silenced Shen, and the two didn't argue so loudly anymore. I couldn't hear anything else."

"What did the man who threatened you on the phone sound like?"

"You're asking if he sounded like Pan Han? I don't know. He was speaking very softly, and I couldn't tell."

Several more police cars arrived, sirens blaring. A group of white-gloved policemen came upstairs with cameras, and the house hummed with activity. Da Shi told w.a.n.g to go back and get some rest.

Instead, w.a.n.g walked into the room with the minicomputer to find Wei. "Can you give me an outline of your three-body evolutionary algorithm? I want to ... introduce it to some people. I know my request is abrupt. If you can't, don't worry about it."

Wei took out a CD and handed it to w.a.n.g. "It's all on here: the whole model and additional doc.u.mentation. Do me a favor and publish it under your own name. That would be a big help."

"No, no! How could I do that?"

Wei pointed at the disk in w.a.n.g's hand and said, "Professor w.a.n.g, I noticed you the first time you came here. You're a good man, a man with a sense of responsibility. That's why I'm counseling you to stay away from this. The world is about to change. Everyone should try to live out the rest of their lives in peace. That would be best. Don't worry too much about other matters. It's all useless anyway."

"You seem to know even more than you let on."

"I spent every day with her. It's impossible to have no inkling."

"Then why not tell the police?"

Wei smiled contemptuously. "The police are worthless. Even if G.o.d were here, it wouldn't do any good. The entire human race has reached the point where no one is listening to their prayers."

Wei was standing next to an east-facing window. Through the gla.s.s, beyond the distant cityscape, the sky was brightening with the first light of dawn. For some reason, the light reminded w.a.n.g of the strange dawn he saw each time he logged on to Three Body.

"In reality, I'm not so detached. I haven't been able to sleep the last few nights. Every morning when I see the sunrise, it feels like sunset." He turned to w.a.n.g, and after a long pause, added, "And it's all because G.o.d, or the Lord she talked about, can't even protect Himself anymore."

17.

Three Body: Newton, Von Neumann, the First Emperor, and Tri-Solar Syzygy The start of the second level of Three Body wasn't too different than the first: still the strange, cold dawn, still that colossal pyramid. But this time, the pyramid was back in the Egyptian style.

w.a.n.g heard the crisp sound of metal striking against metal. The clashing only highlighted the silence of the chilly dawn. Searching for the source, he saw two dark shadows flickering at the foot of the pyramid. In the dim light, metallic glints flashed between the shadows: a swordfight.

Once his eyes had adjusted, w.a.n.g saw the figures more clearly. Based on the shape of the pyramid, this should be someplace in Three Body's version of the East, but the two fighters were Europeans dressed in a sixteenth- or seventeenth-century style. The shorter one ducked below a swinging sword and his silvery wig fell to the ground. After a few more thrusts and parries, another man appeared around the corner of the pyramid and ran toward the fighters. He tried to get the two to stop, but the swinging blades whistling through the air prevented him from getting close.

He shouted, "Stop! Don't you two have anything better to do? Where's your sense of responsibility? If civilization has no future, what good is this supposed bit of glory you're fighting over?"

Both swordfighters ignored him, concentrating on the duel. The taller one suddenly cried out in pain, and his sword fell to the ground with a clang. He turned and ran, holding his wounded arm. The other gave chase for a few steps and spat in the direction of the loser.

"Shameless!" He bent down to pick up his wig. As he straightened up, he saw w.a.n.g. Pointing in the direction of the escapee, he said, "He dared to claim that he invented calculus!" He put on his wig, put a hand over his heart, and bowed courteously to w.a.n.g. "Isaac Newton, at your service."

"Then the one who ran away must be Leibniz?" w.a.n.g asked.

"Indeed, an unscrupulous man. I don't really care about this little claim to fame. Inventing the three laws of mechanics has already made me the greatest, G.o.d excepted. From planetary motion to cell division, everything follows the three great laws. Now, with the powerful mathematical tool that is calculus, it will only be a matter of time before we master the pattern of the motion of the three suns."

"It's not that simple," said the man who had tried to stop the fight. "Have you considered the amount of calculation that's needed? I saw the differential equations you listed, and I don't think an a.n.a.lytical solution is possible, only a numerical one. However, the calculating capacity required is such that even if all of the world's mathematicians worked without pause, they'd still not be able to complete them by the time the world ended. Of course, if we can't figure out the pattern of the suns' movements soon, the end of the world will not be too far away." He bowed at w.a.n.g as well, a more modern bow. "Von Neumann."

"Didn't you bring us thousands of miles to the East specifically to solve the problem of calculating these equations?" Newton asked. Then he turned to w.a.n.g. "Norbert Wiener and that degenerate who just ran away also came with us. We encountered some pirates near Madagascar. Wiener fought the pirates by himself so that the rest of us could escape, and he died valiantly."

"Why did you have to come to the East to build a computer?" w.a.n.g asked Von Neumann.

Von Neumann and Newton looked at each other, puzzled. "A computer? A computing machine! Such a thing exists?"

"You don't know about computers? Then what did you have in mind for completing the vast amount of calculations?"

Von Neumann stared at w.a.n.g with wide-open eyes, as though his question made no sense. "Using people, of course. Other than people, what else in the world is capable of performing calculations?"

"But you just said that all the mathematicians in the world wouldn't be enough."

"Instead of mathematicians, we'll use common laborers. But we need many of them, at least thirty million. We'll do mathematics using human wave tactics."

"Common laborers? Thirty million?" w.a.n.g was amazed. "But if I recall correctly, this is an age when ninety percent of the population are illiterate. Yet you want to find thirty million people who understand calculus?"

"Have you heard the joke about the Army of Sichuan?" Von Neumann took out a thick cigar, bit off the end, and lit it. "Some soldiers were being drilled, but because they had no education, they couldn't even follow the drill instructor's simple orders to march LEFT-RIGHT-LEFT. So the instructor came up with a solution: He had every soldier wear a straw shoe on the left foot and a cloth shoe on the right. When they marched, he shouted"-here he switched to a Sichuan accent-"STRAW-CLOTH-STRAW-CLOTH.... That's the kind of soldier we need. Except we need thirty million of them."

Hearing this modern joke, w.a.n.g knew that the man before him wasn't a program but a real person, and almost certainly Chinese.

"It's hard to imagine such a large army," w.a.n.g said, shaking his head.

"That's why we've come to see Qin Shi Huang, the First Emperor." Newton pointed at the pyramid.

"He's still in charge?" w.a.n.g looked around. He saw that the soldiers guarding the entrance to the pyramid really were equipped with the simple leather armor and ji-style halberds of the Qin Dynasty. The anachronistic mix of historical elements in Three Body no longer surprised him.

"The whole world is going to be under his rule because he has an army of more than thirty million preparing to conquer Europe. All right, let's go see him." Von Neumann turned to Newton. "Drop the sword." Newton obeyed.

The three of them entered the pyramid, and just as they were about to emerge from the tunnel into the Great Hall, a guard insisted that they strip off all their clothes. Newton objected. "We're famous scholars. No one of our stature would carry hidden weapons!"

As the two sides explored this stalemate, a deep, male voice came from the Great Hall. "Is it the foreigner who discovered the three laws of motion? Let him and his companions in."

They entered the Great Hall. The First Emperor was pacing back and forth, his robe and his famous long sword both dragging along the ground. As he turned to gaze at the three scholars, w.a.n.g realized that his eyes were the same as the eyes of King Zhou of Shang and Pope Gregory.

"I already know the purpose of your visit. You're Europeans. Why not go find Caesar? His empire is vast. Surely he can find you thirty million men."

"But my most honored Emperor, do you know what kind of army he has? Do you know what shape his empire is in? In the magnificent eternal city of Rome, even the river that flows through the city has been heavily polluted. Do you know the cause?"

"Military industrial production?"

"No, Great Emperor, it's the vomit from Romans after their binge and purge feasts. When the n.o.bles attend the feasts, stretchers have already been prepared for them under the tables. When they've eaten so much that they can no longer move, the servants carry them home. The entire empire has sunk into a quagmire of extravagance from which they cannot extricate themselves. Even if Caesar could organize an army of thirty million, it would not have the quality and strength necessary to perform this great calculation."

"I am aware of that," Qin Shi Huang said. "But Caesar is waking up and reinvigorating his army. The wisdom of Westerners is terrifying. You are not more intelligent than the men of the East, but you can see the right path. For example, Copernicus could figure out that there are three suns, and you could come up with your three laws. These are very impressive accomplishments. We here in the East cannot, for now, match them. I don't possess the ability to conquer Europe. My ships are not good enough, and the supply lines cannot be maintained for long enough to go over land."

"That's why your empire must continue to develop, Great Emperor!" Von Neumann seized the opportunity. "If you can master the pattern of the suns' movements, you will be able to make the most of each Stable Era, and also avoid the damage brought by each Chaotic Era. This way, your progress will be much faster than Europe's. Believe us, we're scholars. As long as we can use the three laws of motion and calculus to accurately forecast the movements of the suns, we do not care who conquers the world."

"Of course I need to predict the suns' movements. But if you want me to gather thirty million men, you must at least demonstrate for me how such calculations would be conducted."

"Your Imperial Majesty, please give me three soldiers. I will demonstrate." Von Neumann grew excited.

"Three? Only three? I can easily give you three thousand." Qin Shi Huang glanced at Von Neumann, distrustful.

"Your Imperial Majesty, you mentioned just now the defect in the Eastern mind when it comes to scientific thinking. This is because you have not realized that even the complicated objects of the universe are made from the simplest elements. I only need three."

Qin Shi Huang waved his hand and three soldiers came forward. They were all very young. Like other Qin soldiers, they moved like order-obeying machines.

"I don't know your names," Von Neumann said, tapping the shoulders of two of the soldiers. "The two of you will be responsible for signal input, so I'll call you 'Input 1' and 'Input 2.'" He pointed to the last soldier. "You will be responsible for signal output, so I'll call you 'Output.'" He shoved the soldiers to where he wanted them to stand. "Form a triangle. Like this. Output is the apex. Input 1 and Input 2 form the base."

"You could have just told them to stand in the Wedge Attack Formation," Qin Shi Huang said, glancing at Von Neumann contemptuously.

Newton took out six small flags: three white, three black. Von Neumann handed them out to the three soldiers so that each held a black flag and a white flag. "White represents 0; black represents 1. Good. Now, listen to me. Output, you turn around and look at Input 1 and Input 2. If they both raise black flags, you raise a black flag as well. Under all other circ.u.mstances, you raise the white flag."

"I think you should use some other color," Qin Shi Huang said. "White means surrender."