The wild animals of the island of Mata Nui, the Rahi, have been corrupted by the evil Makuta, who is using them to attack the villagers and take control of the island for himself.[4] After descending from the sky in their Toa canisters, the six Toa drift aimlessly in the ocean but are summoned to the island, arriving across its six regions. Onua (the Toa of earth), is the first to awaken, followed by Gali (the Toa of water), Pohatu (the Toa of stone), Kopaka (the Toa of ice), Lewa (the Toa of air), and Tahu (the Toa of fire). The Toa search for Kanohi, powerful masks that grant them new abilities, while aiding the island's villages and defeating Makuta's six elemental monsters.

The Toa briefly converse with each other during the quest, also sharing their collected Kanohi with each other. After gathering all of the Kanohi and defeating all six elemental monsters, the Toa team up and enter Makuta's lair, hidden underneath an ancient temple. Inside, two groups of three Toa each combine into the two Toa Kaita and defeat the Manas, powerful minions of Makuta. The Toa Kaita dissolve back into their original forms and conquer six different areas of Makuta's lair before facing and defeating Makuta,[b] releasing a light from the temple visible across the entire island. As the villages celebrate Makuta's demise, a creature awakens underneath the island.