The Dark Forest

Fitzroy and Ringier observe images of the Trisolar fleet. They determine probes sent out by the ships, travelling faster than the rest of the fleet. The team suspects the probes’ launch date to be the same as the announcement of Luo Ji’s Wallfacer plans. Fitzroy calls Luo Ji “God.”

Yang Jinwen, Miao Fuquan, and Zhang Yuanchao watch the test of Tianti III, the third space elevator, on television. Zhang Yuanchao’s son brings him his new ration cards and the three discuss the trying times ahead of them, comparing the stringent restriction of resources to other difficult times in Chinese history. They turn to the future and their own deaths. Yang Jinwen’s son works in space and Yang Jinwen has it arranged so that his remains will be shot out into space. Miao Fuquan will have his buried deep in a mine. Both want their remains untouched by Trisolaris.

Zhang Beihai visits Ding Yi to convince him to slow fusion research for space travel in order to not imbalance research. He doesn’t want resources and time to be split and hinder his preferred method of research. His plan to send political cadres as reinforcements to the future is approved and the program begins. He buys three iron meteorites with which he makes 32 bullets. These bullets can pierce a space suit and shatter upon impact. With the bullets, he travels through space to the Yellow River Station and assassinates three scientific figures and two bystanders in what he hopes looks like a chance meteor shower. He hopes that the deaths of the scientists will cause his alternative scientific method to become the primary point of research.

The ETO discuss Beihai’s actions in Three Body and assert that defeatism is more dangerous than triumphalism to their goals. Defeatism creates a desperation harder to control than the short-sighted belief in victory. Meanwhile, Chang Weisi bids farewell to Zhang Beihai, who, along with others, will now hibernate for the future. He admires Zhang Beihai’s firm faith in their victory but truly doesn’t understand where his beliefs come from, and now, he never will.

Hines and Rey Diaz wake from hibernation after 8 years because large investments have helped develop their projects quickly. Hines meets with his wife Keiko Yamasuki, another brilliant neuroscientist, who tells him that while their early designs failed, they were able to make a holographic map of the brain to locate critical thinking. They visit one of the test subjects, Subject 104, who develops a fear of water after answering false to one of the project’s prompts about whether water is toxic or not. Not understanding how this happens, Hines tests it himself and develops a fear of water as well.

Their discovery leads Hines to suggest that PDC use this research to reprogram soldiers’ brains away from defeatism, like his brain was reprogrammed to fear water. At the next PDC hearing, Hines’ proposed “mental seal” is met with steep opposition. Members see it as an invasion of free will and a violation of human rights. The PDC vote to only make it available to military personnel on a volunteer basis.

Hines and Keiko open a Faith Center to attract volunteers outside of the UN but receive no visitors until the third day. Their first volunteer is a drunk man wanting a seal that will convince him that his wife is not cheating on him. After they throw him out, Wu Yue arrives, looking to gain peace rather than overcome his defeatism. Hines refuses, but sympathizes with him, showing him that he almost sealed himself with the belief that God is dead. On the fourth day, soldiers come to obtain the seal and they find that it works. With their plan in place, Keiko and Hines decide to hibernate until the probes arrive. As they freeze, Keiko has an epiphany. No one notices and she is hibernated, delaying her breakthrough.

As the only Wallfacer not dead or hibernating, Rey Diaz requests his bomb be tested underground on Mercury at a PDC hearing. He not only wants to test its effectiveness but also clear room for a military base in case of a last stand against the Trisolarans. His next request shocks the PDC, as he asks for 1,000,000 hydrogen bombs. Without the resources to complete this request, the representatives from the US, the UK, and France put forward a resolution to cut off his funding. They are unsuccessful and his plan goes forward. They are unable to dig as deeply as they want to on Mercury, meaning that rock is ejected into orbit, creating a ring around Mercury. This show of force impresses the PDC, who seek to make more bombs.

In his bunker, hiding from the sun, Rey Diaz is confronted by his Wallbreaker who is posing as a psychiatrist. He reveals Rey Diaz’s plan to use the bombs to propel Mercury into the sun, causing it to spew stellar matter, cooking the other terrestrial planets and pulling them in, growing the stellar matter field until the entire solar system is sucked into the sun and destroyed. This would doom both the human and Trisolar civilizations to certain death. Rey Diaz would use this threat of mutually assured destruction to win a victory for humanity, forcing the Trisolar fleet to abandon their invasion. His plan is the source of his fear of the sun. The Wallbreaker saw through his plans because of the tests on Mercury, although it would not be possible to make enough bombs to see the plan come to fruition. Rey Diaz attacks his Wallbreaker and nearly kills him before his guards pull him off.

At the subsequent PDC hearing, Rey Diaz’s is stripped of his power as a Wallfacer, and some representatives even want to try him for crimes against humanity. Before it can escalate, Rey Diaz informs the PDC that he has a kill switch on his watch that will detonate a bomb somewhere in NYC if he so chooses and that only he can stop it. Rey Diaz demands that he be allowed to return home safely and, with his plan officially ended, his fear of the sun dissipates. He is escorted to Venezuela, where he reveal that there is no kill switch or bomb. On the streets of Venezuela, Rey Diaz is stoned to death by his people for his future crimes against humanity.

As the 22nd century passes, characters who are not in hibernation live out their lives and die naturally. New humans are born.