Nestled in the Milky Way Galaxy four light-years away from the Earth, Trisolaris is a planet in a three-star solar system. The stars move in erratic orbits that follow no clear patterns—this is the classic “three body problem.” No civilization in Trisolaran history has been able to predict—and thus survive—the chaotic eras caused by these unpredictable orbits. The present Trisolarans, recognizing this, have begun their search for another home in the universe. Meanwhile, on Earth, our protagonist Ye makes contact with the Trisolarans via the opening of SETI communication channels. Her message is short, but it sets the course for the collision of the two worlds: “Come here!