The Bionicle universe is centered around the conflict between the warring spirits of light and darkness. On the island of Mata Nui, named for the Spirit which protected the villagers(known as Matorans), the Brotherhood of Makuta terrorizes the populace. The evil creature Makuta infects creatures of the island and turns them against the Matorans. The heroes of the storyline, the Toa, arrive on the island and decide to help the villagers in beating back Makuta. They track down the masks of power and use them to defeat Makuta once and for all. The story then branches off into various directions, looking at how the Matorans arrived on Mata Nui as well as looking at the struggles against Makuta made by other Toa on different islands.