The story takes place on the distant planet of Lumimaire. The conflict of the plot revolves around the need to control the Lightstar Crystal. This powerful crystal powers the great city of Luminicity. Baron Dark, the show's main villain, tried to steal the crystal in order to gain control over its incredible power. He only succeeded in obtaining half of the crystal, with the other half being obtained by Prince Lightstar. The half of the crystal that the Baron Dark managed to obtain turns him into a living skeleton. It also gives him the power to turn those with evil hearts into living skeletons for his army. Each episode involves Prince Lightstar, his siblings and Baron Dark attempting to obtain the other half of their respective crystals in order to gain control over the planet. Prince Lightstar forms part of the Legion of Light. It consists of Justin Lightstar a.k.a. Prince Lightstar, Joshua Lightstar a.k.a. Grimskull, and Jennifer Lightstar a.k.a. Talyn. They also have been endowed with great powers through their half of the Crystal. They team together with their uncle Ursak to battle the evil Baron Dark. While Baron Dark is transformed into an undead skeleton and given the ability to transform other living beings into his Skeleton Warriors, the Legion of Light gains other fantastic abilities. Lightstar gains the ability to channel energy through his hands, Talyn gains the power of flight, and Grimskull is transformed into an undead creature similar to the Baron, but also has the power to travel through shadows.