The Three-Body Problem: Chapter 16 Summary & Analysis

As soon as Wang logs off, he gets a call from Shi asking him to come to his office. When he arrives, he is met by computer specialist Xu Bingbing and Wei Cheng, Shen Yufei’s spacey husband. Wei explains that his life is in danger, though General Chang and the rest of the Battle Command Center do not know this yet. At Shi’s urging, Wei begins to tell Wang his life story.

As Wei tells it, he was always a lazy person, ever since childhood. Though he had an amazing, inborn      aptitude for geometry—shapes immediately became numbers in his mind—he was too lazy to ever apply this gift. Eventually, Wei got a series of degrees, but when he finally got a job at a college, he was too bored to take teaching seriously. Instead, he went to a Buddhist monastery to find some peace and meaning in his life. The abbot at the monastery encouraged Wei to embrace his sense of emptiness: “you must use this existential emptiness to fill yourself.”

As he fell asleep that night, Wei imagined a sphere to symbolize his emptiness. When that initial empty sphere reminded him of death, he pictured a second sphere. Unfortunately, in this image, the spheres’ separate gravities always pulled them into a stable rotation around each other, which also made Wei think of death. Only when he introduced a third sphere into his mind did the emptiness take on unpredictability and a kind of life. The three spheres danced in Wei’s mind until he fell asleep.

Wei had effectively discovered the three-body problem on his own. Though years earlier, a mathematician named Henri Poincaré had declared the problem unsolvable, Wei believed a new kind of approach might work—namely, an evolutionary algorithm. Such an algorithm would at each moment lay out the options for what could happen next in the three bodies’ motions, and it would “preserve the advantaged” possibilities over the disadvantaged ones in order to form more accurate predictions. 

Such an algorithm would take a tremendous amount of computing power, and Wei only had paper at the monastery. Still, Wei worked tirelessly, discarding his notes as he went. A few days later, a young woman—Shen Yufei—came to Wei’s room, holding his scrap paper and telling him he was “brilliant.” Shen promised to help Wei get the computing power he needed to work on the three-body problem. Wei felt stirrings of attraction for Shen.

That night, Wei saw Shen praying at a temple on the monastery grounds. When he got closer, he heard her say, “Buddha, please help my Lord break away from the sea of misery.” When Wei asked Shen if this Lord was part of Buddhism, she said no and hurried away. With the help of another monk at the monastery, Wei concluded that if Shen was praying to Buddha to help a mysterious Lord, then this Lord must actually, tangibly exist. 

Though the monks warned him against it, Wei left with Shen. Soon after, the two were married, though there was never any real passion or love; Shen was only interested in solving the three-body problem. While Shen worked on the Frontiers of Science, Wei was trying to improve his algorithm. For the most part, the two had lived in peace—until yesterday.

Wei says that yesterday, a man called him and told him that unless he stopped researching the three-body problem, he would be killed. Then, later that night, Shen had threatened her husband with a gun, telling him that if he stopped working on the problem, she would kill him herself. Shen told him that he would become “the savior of the world” if he successfully solved the three-body problem. But if he stopped, he would be a “sinner.” “If someone were to save or destroy the human race,” she said, “then your possible contribution or sin would be exactly twice as much as his.” Shi, Wang, and Wei are all confused by this strange language.

To continue the investigation on Wei’s behalf, Wang leaves with Shi and Xu Bingbing (the computer specialist). As they drive away, Xu mentions the Three Body game to Wang and explains that she is responsible for monitoring it. When Wang asks for more information, however, Xu explains that she does not understand where the game has come from. Wang is startled by the coincidence, but Xu assures him that they must believe Shi’s famous slogan: “all this must be the work of people.” Wang begins to believe that Xu and Shi are both lying to him.

Wang, Xu, and Shi arrive at Shen’s house, but they are too late—she has already been shot and killed. Shi nervously tries to figure out who committed the crime. Wei is not very upset, even when Shi tells him that the murderer probably wanted to kill Wei most of all. Wei admits that there were a few other things he was “too lazy” to tell Shi at first.  

Now, Wei confesses that when Pan Han had arrived at this house, he and Shen had fought. They had spoken of warring sides in a conflict; they mentioned the Adventists and the Redemptionists, and though both groups wanted to bring the Lord to earth, each group had a very different expectation of what would happen when the Lord arrived. Specifically, Pan wanted the Lord to punish humanity, whereas Shen seemed to want no such thing. Wei realizes that the voice that threatened him on the phone probably belonged to Pan.

Wei gives Wang a disk with all of his mathematical work on the three-body problem; he encourages Wang to publish the disk under his own name, because he is “a good man, a man with a sense of responsibility.” Wei explains that he is filled with a sense of doom—sunrise now seems like sunset to him. “And,” he tells Wang, “it’s all because God, or the Lord she talked about, can’t even protect Himself anymore.”