With the destruction of planet Tek, the sole survivor, princess Tekla accompanied by Voxx travels to another system to warn all planets about the Beast Invaders. She crash lands on planet Ice where a quarrel between the Royal legion of King Cryos confronts a Rock expeditionary mining squad, including Graveheart. A Beast cohort launches a full-scale attack and only the Ice sovereign, Graveheart and a convalescent Tekla survive the first purge. King Cryos and his aides heal their former adversary and welcome Graveheart in joining the Alliance. Meanwhile, the Beast Armada invades the system and begins preparations.

The Aurora, Cryos' flagship, travels to planet Rock to convince Lord Mantle to join the Alliance. Sadly, the army arrests Graveheart and the Rock King expels the Ice King determining he is still his greatest enemy. Lord Mantle condemns Graveheart to imprisonment. Meanwhile, Blokk the supreme warlord of the Beast launches an invasion on planet Rock with Voyd permission. Jade, a rock commander and a long time friend of Graveheart, releases him and they run to the Core central to activate the planet's defense – the Battle Moons. They succeed but Lord Mantle banishes the “miner” still not believing in the alliance. Despite all odds, Jade agrees to join them, claiming to need to watch her friend's back.

The Beast Planet demonstrates its might, launching an armada to attack Fire while training its powerful cannons on the Battle Moons. A stray blast threatens to destroy Ice, but Tekla and Lady Zera discover world engines hidden within the planet, which move it out of the path of the blast.

The episode opens with Lord Mantle's funeral. As Graveheart speaks and the Alliance watches, Blokk kills three Rock soldiers. Tekla, Pyrus and Zera confront Jade to demand why she would betray them, and Graveheart reveals that it was to convince Mantle to lend them the Battle Moons for the fight with Remora. Graveheart then asks Jade to be the next ruler of Rock. Blokk enters the World Engine and kills all the Rock soldiers except the captain. He steers the planet towards the closest star. He then contacts the Alliance and demands that Graveheart face him. Voxx repairs the world engine allowing Jade to steer the planet away as Graveheart finishes Blokk off by plunging the Forcefield Generator inside him. In the aftermath, Jade makes Graveheart an official Rock citizen, and the series ends with the Beast Planet devouring another planet, the subtitle below echoing the first episode: "Planet Reptizar: On Doomsday".