Half a century after the Doomsday Battle, the uneasy balance of Dark Forest Deterrence helps to keep the Trisolaran invaders away. Earth enjoys unparalleled prosperity due to the infusion of Trisolaran knowledge and, with human science advancing as well as the Trisolarans implementing Earth culture, it appears that the two civilizations can co-exist peacefully as equals without the terrible risk of mutually assured annihilation. But serenity has made humanity complacent. Cheng Xin, an aerospace engineer in the 21st century, awakens from hibernation in this new age. She brings understanding of a long-forgotten system dating right away of the Trisolar Problems, and her presence may annoyed the delicate stability between two worlds. Will mankind grab the superstars or perish in its cradle?