After escaping from Planet Doom aboard a stolen slave ship, the five space explorers are chased to Planet Arus by Yurak's forces. Crash landing on the worn torn planet, the five youn men find themselves unwelcomed by the citizens, who are afraid of what will happen to them.

The slowly make their away across the desert to the ruined castle, in hopes that they will be able to find the secret to the legend of Voltron. There, they are greeted by Coran, the Castle Magistrate, who relates to them, the story of how Arus was once a beautiful planet within the Diamond Galaxy, and thusly destroyed by King Zarkon's forces. He however, looks over the young Princess Allura, the last survivor of the royal family and daughter to King Alfor, the man who created Voltron.

The five space explorers vow to help resurrect the fallen robot defender and to help protect Arus against King Zarkon's forces. With Yurak adamant on finding them, Coran tells them of the locations of each Lion robot, in hopes that they will uncover secret to join them together to form Voltron