The second season focuses on the Alliance's efforts to avoid the unstoppable Beast Planet. Each world in the Cluster is discovered to be equipped with "World Engines", massive drive systems which can propel the planets through space. Using these, the worlds of the Cluster flee the Beast; Fire's engine is damaged and the planet is thus sacrificed in a futile attempt to stop the Beast. Fire's population is moved to the remaining Battle Moons, now down to three following the battle to save Fire. On their journey, they discover Planet Sand, which joins the Alliance, and Planet Jungle, which the Alliance blows up when the Beast tries to consume it; this, too, proves useless. The plants of Jungle live on as a single cutting which is given to Emperor Femur of Bone.