During the Cultural Revolution, the military's top-secret alien civilization exploration project, the Red Coast Project, makes a breakthrough. But at the moment the launch button is pressed, Ye Wenjie, who has gone through many hardships, doesn't realize that she has fundamentally changed the fate of humanity. Earth civilization's first cry to the universe, centered on the sun, travels at the speed of light to the depths of the universe... Four light-years away, the Three-Body civilization is struggling—under the rule of three irregularly orbiting suns...