A group of young scientists in the U.K. struggle with the inexplicable fact that their experiments no longer make sense, apparently leading to the suicide of a friend and colleague. In 1960s China, Ye Wenjie is sent to a work camp after watching her father's death at the hands of the state amidst the Cultural Revolution.
As the world looks for an explanation for the flickering of the stars, Jin Cheng and Jack Rooney explore the virtual landscape. In the past, Ye Wenjie proposes a method for reaching out to intelligent life in the galaxy.
Jin and Jack face disturbing new challenges when they enter the game in two-player mode, and find that they are unable to save a young girl from repeated catastrophes. Auggie's employers pressure her to resume her nanofiber project.
While Jin and her friends reel from the news of another shocking death, the team investigating the larger conspiracy plan to use Jin to gain access to a secret society that is making preparation for the arrival of an alien species. In the 1980s, Ye Wenjie is introduced to a new world she helped to create.
After Detective Shi questions Ye Wenjie about the San-Ti, Wade considers how to seize intelligence about the coming alien threat from the Judgment Day. Shi convinces Auggie to resume her nanofiber work.
The nations of Earth fall into chaos after the revelation that the San-Ti are coming, and Ye Wenjie has a reckoning with her choices. Jin joins Wade's team to find a way to fight back, while Will considers one final choice at the end of his life.
Wade announces his intention for Project Staircase to send a human passenger to meet the San-Ti – but with one major caveat. Will considers a new possibility at the end of his life, and Jin learns the truth.
After a shocking accident Detective Shi brings Saul to the international council preparing for the planet's defense, where he learns that the group intends to recruit him. Jin prepares for Project Staircase's big launch, and the San-Ti's followers reach out to Tatiana Haas.