Somewhere in the Orion Arm of the Milky Way Galaxy, an alien worker, nicknamed Singer, is tasked with determining the sincerity of coordinates and cleansing them. Singer notices a series of interesting communications between two worlds, one of which has already been cleansed, and Singer theorizes that it’s because of nearby “slow fog.” Singer takes an interest in the world that originally sent the message, even giving them a nickname of the “star pluckers.” There isn’t much time for investigation as cleansing is just a routine task. Singer is about to use a “mass dot” to cleanse when it’s noticed the system has “blind corners” and instead decides to use a two-vector foil instead as Singer flicks it and continues on singing.
Cheng Xin and AA awake from hibernation only 60 years later and are greeted by Cao Bin over a video call. Since they had asked to be awoken in the event of a dark forest strike, they ask when the photoid is expected to hit the sun.. but Cao Bin tells them the means of the attack is instead a “slip of paper”
A year previous, workers aboard an advance warning station noticed an object traveling towards the solar system. They move to intercept it when they noticed it had slowed down, and observe that it is about the size of a credit card with no mass, perfectly flat, and emitting gravitational waves. They notice that it seems to not interact with their world at all as it easily passes through ships and even people. It is not until the gravitational waves stop that they realize the sinister nature of it as everything around starts falling into the object and becomes two-dimensionalized, the same fate that will become of the entire solar system.
With the knowledge that escape from the dimensional strike is impossible without the proper escape velocity of lightspeed, Cheng Xin and AA take a mission to visit Luo Ji, who is currently on Pluto as the caretaker of the Earth Civilization Museum, a repository of all the precious artifacts on Earth, a project conceived by UN Secretary Say centuries ago.
When they arrive, they see giant letters carved into the rock that say “Earth Civilization.” They meet with Luo Ji and tell him they are tasked with taking the artifacts and distributing them throughout space in the hopes that they might be recoverable by some civilization millions of years into the future after everything has been two-dimensionalized.
As they start gathering the artifacts, they see the solar system start to be two-dimensionalized, first Neptune and Saturn, followed by Earth, Mercury, the Sun, Venus, Mars, and Jupiter. Each one turned into an enormous 1:1 scale painting of the body, with each part laid flat, looking like a series of concentric circles.
As they start to make their final run, Luo Ji says that he wants to stay back on Pluto. Aboard Halo Cheng Xin and AA ask him if they can keep Starry Night with them, Luo Ji tells them the incredible news that not only did he help with lightspeed research that continued after the events that had caused it to get shut down, but one of the curvature propulsion drives they had made was installed on Halo, and they would be the only 2 people to escape two-dimensionalization.
Shocked at the revelation and ordered to not come back for Luo Ji, they try to think of a destination in the vastness of the universe. Cheng Xin decides to keep her date that she had made with Yun Tianming and sets course to DX3906, “Our Star.”