Ye Wenjie tells us the backstory and danger of Mike Evans, a self-described “pan-species communist” billionaire that stars the ETO with Ye. In order to continue to receive messages from Trisolaris, he builds a second Red Coast Base on a oil tanker renamed Judgement Day
With the collected messages from Trisolarais are onboard Judgement Day, and Da Shi comes up with a “demonic” plan to obtain them before they can be destroyed by the crew. He uses Wang Miao’s “flying blade” nanomaterial, stretched across the Panama Canal to slice the ship into slices.
Da Shi’s plan is successful, and via the messages we’re given a Trisolaran perspective on the events of the book. The original message that Ye Wenjie sent was received from a pacifist Listener who warns her to not respond to ensure that the Earth is not conquered by members of his species.
However, Ye’s response ultimately gives away the location of Earth, and the Trisolarans get to work on developing a faster way of communication. After a few false starts, they develop a way to unfold an 11-dimensional proton into 2 dimensions allowing them to imprint computer circutity onto the surface before folding back to 11 dimensions and sending what they call Sophons, at light speed towards Earth.
Once the Sophons reach Earth, they're able to communicate via quantum entanglement across great distances. Since the Trisolarans are worried about the speed of human scientific progress, they task the Sophons to sabotage and block human scientific progress by interfering with particle accelerators and causing the other “miracles.”
One of the miracles is the ability to convey messages directly onto retinas, the method that Trisolaris uses to convey their feeling towards the insignificant human race: “You’re bugs!”
Finally, we end with Ye returning to the long-forgotten site of Red Coast Base, now rusty and covered in vines. Upon seeing the sunset, she whispers, “My sunset, and sunset for humanity.”