When a rogue planet threatens a new Human colony, Valerian and Laureline are sent to investigate and discover a barren, rocky surface – and a whole world beneath it! The people who live inside Zahir have never seen the stars. Divided along gender lines, torn by a senseless and bloody war, they are unaware that their planet is hurtling towards disaster. To stop it, the two agents of Galaxity will have to infiltrate both sides and force a reconciliation.