Book's homeworld, a lush planet whose people share an empathic bond with nature, destroyed by the Dark Matter Anomaly in the 32nd century.
Kwejian is the homeworld of Cleveland Booker, known as Book, in the 32nd century. It is a planet of rich forests and wildlife, and its people, the Kwejians, share an empathic bond with living things around them. Book could feel this connection, which he used to communicate with animals and to sense the natural world.
In Discovery's fourth season, Kwejian was destroyed by the Dark Matter Anomaly, a huge and mysterious gravitational disturbance that moved unpredictably through the galaxy. Michael Burnham and Book tried to save the planet, but they could only rescue a small number of people. Book's family, including his nephew Leto, died in the disaster. Book's grief over Kwejian drove much of his story that season, leading him to make dangerous choices in an attempt to stop the anomaly.
The loss of Kwejian is one of Discovery's most powerful tragedies. It deepened Book's character and his relationship with Burnham, and its destruction gave the fourth season its personal stakes and the conflict that tested the Federation's unity.