The Dark Forest

After the captain of Ultimate Law dies by suicide, Dongfang Yanxu calls a meeting with her two vice-captains. She thinks that they have to act quickly, but Dongfang Yanxu can’t bring herself to say what she thinks must be done. She and the two vice-captains have a wordless conversation with their eyes. They think that interstellar dust will slow down their spacecraft, so they won’t reach the star they’re aiming for until another 60,000 years have passed. They’re afraid everyone will die by then. To avoid that issue, they think about putting everyone on the five ships into one or two ships and using the fuel from the deserted ships, but there isn’t enough space for everyone on just one or two ships. That means that some people must die so that others can survive.

Dongfang Yanxu and her vice-captains begin to contemplate bombing the other ships so their ship can survive. They think the choice is horrific, but they don’t know whether the other ships are contemplating the same plan. They turn over and over the idea that they don’t know what other ships are thinking, and they don’t know if they’re thinking the same things that Dongfang Yanxu and the vice captains are thinking. They call that way of thinking a chain of suspicion. Ultimately, they conclude that they must act if only to prevent the possibility that one of the other ships will bomb them. Dongfang Yanxu goes to Zhang Beihai, who has already concluded that bombing the other ships is necessary. Zhang Beihai targets the other ships, but just before he presses the button, their ship, the Natural Selection, is bombed, killing everyone on board.

Ultimate Law is the ship that bombed Natural Selection and the three other ships. The bombs are detonated far enough away from the ship that they kill everyone on board but only cause minimal damage to the ships themselves. One ship, the Blue Space, previously prepared for an attack by vacuum-sealing the interior. Everyone on board survives the bombing, and Blue Space fires lasers at Ultimate Law, causing Ultimate Law to explode. Blue Space then goes to each of the now empty ships to secure fuel and backup parts. The fight becomes known as the Battle of Darkness. Something similar happens on the other side of the solar system, where Bronze Age attacks Quantum. Blue Space and Bronze Age travel in opposite directions, and both ships then cut off all contact with Earth.

After Luo Ji hears about the Battle of Darkness, he tells Shi Qiang that his suspicions have been confirmed, and he holds the key to human success and victory. Shi Qiang doesn’t know what Luo Ji means but decides to help him anyway. At first, Luo Ji doesn’t want Shi Qiang to help because Luo Ji thinks the probe, which is currently hurtling toward Earth, aims to kill him (Luo Ji), and he doesn’t want Shi Qiang to be hurt or killed in the crossfire. Ultimately, though, Luo Ji accepts Shi Qiang’s help, and they decide to go see the mayor of the underground city.

The underground city has descended into chaos and pandemonium. People run and scream across the city, and an orgy of over a hundred thousand people has broken out in the center of town. After Luo Ji tells the mayor what he would need him to do, the mayor says that even if he wanted to help, he wouldn’t be able to. He says that he isn’t connected to the higher-up people in power who Luo Ji would need to contact. The Trisolaran probe is predicted to reach Earth in about five hours at that point, and Luo Ji says he and Shi Qiang need to leave so that when it comes, it won’t destroy the underground city and kill everyone in it.