Warning: The following page/section contains spoilers. Please read at your own risk.
After defeating Makuta and exploring the island of Mata Nui, the Toa Metru attempt to take an underground path back to Metru Nui. On the way, however, Nokama is mortally poisoned during a battle with the Rahi Nui. Vakama wishes to push on anyway, but comes to a head with Whenua when he refuses to continue without her. However, the party is surprised when the Karzahni plant suddenly appears. When Vakama asks what the plant wants of them, it explains that it wanted vengeance, though since he cannot have it he desires to turn his wrath against them. Vakama, however, states that he cannot have his full vengeance unless all of them are alive, which causes the plant to back down, and he explains that, because the Toa Metru sealed Makuta away, he cannot exact his vengeance. He then temporarily cures Nokama and explains to the Toa Metru that in exchange for her full curing he wants them to retrieve a vial of Energized Protodermis for him. The Toa agree and head off to obtain the substance.