It is a direct sequel to Bionicle 2: Legends of Metru Nui, and largely adapts the 2005 storyline with the majority of events taking place before the previous film's ending.

This figure is later revealed to be Roodaka, the queen of the Visorak horde, and she is later shown infusing the shard into her chest as a heartstone as she vows to free Makuta from his prison.

Combining their elemental powers to seal the Makuta in protodermis, the Toa left Metru Nui to find a home for the sleeping Matoran, vowing to return to the city to rescue those they were forced to leave behind.

As they will remain Hordika forever if the venom is not neutralized in time, their only hope of changing back is to find an ancient hermit-like Rahi named Keetongu, which many consider a myth.

Vakama grows agitated over continually being blamed for the Toa's current situation and storms off, choosing to try and save the Matoran alone, but is cornered by Visorak and once again captured.

Roodaka takes advantage of Vakama's current state of mind by offering him a proposal: if he commands the Visorak horde, he can rule Metru Nui.

Using inscriptions translated before the attack, the group follows a trail that leads them to Keetongu's lair at the top of the Ko-Metru district.

After the other five Toa unsuccessfully attempt to defeat Roodaka by firing their elemental spinner weapons at her, Vakama reveals his change of heart and orders the Visorak to leave and be free; having been placed under his command, the horde obeys.

Turaga Vakama concludes the story of the Toa Metru that he had been recounting to Takanuva, Jaller, and Hahli following the events of the first film.

The computer-generated effects were praised by some critics, stating that they could be appreciated even though the film was geared toward teenagers and young people.