On Kentoku Archipelago, the First Son of Clan Fursic, Kuno – engaged for political reasons to Yumiwa, the eldest of the Empress’ daughters, of clan Umbraline – hatches a number of unsuccessful schemes to launch a full-scale invasion force to Mata Nui.
Makuta – gone from the island, but not dead - spends the last of his lingering influence to guide some of his former servants to vials of Antidermis.
The Antidermis augments these beings’ power and wickedness, and soon a small group led by the Dark Toa Echelon known as "The Legacy" congregates.
Zaktan is among the beings led to Antidermis, and in his mind Makuta tells him that the Antidermis is the answer to getting past the Abettor.
After unsuccessfully trying to reach the Abettor’s tunnel alone, Zaktan returns to the Piraka bungalow for help.
Zaktan is fought by the rest of the Piraka, but the battle stops as Zaktan shows the Antidermis, and suggests a “rescue” run into Ta-Koro (Vezok having been captured by the Ta-Koro Guard).
The Piraka cause havoc in Ta-Koro until the Toa Maru arrive.
The Piraka flee to the entrance of the Dark Walk, and cause a cave-in at their backs to defray pursuit.
Yumiwa throws an elaborate party for the Dasaka nobility, where a second, larger expedition to Mata Nui is announced.
The Empress herself shows up as a surprise guest, but is assassinated by a weapon incriminating Jasik, the First Son of Clan Dastana.
Following her mother’s death, Yumiwa ascends to the throne, and the Mata Nui expedition submarine, christened the Chiisai Ryuu, departs from the Archipelago.
Upon reaching the Abettor's tunnel in Mangaia, Zaktan throws his vial of Antidermis at the Abettor, corrupting the guardian to consider the Piraka "worthy" of entering the Vault.
Inside, the Piraka find a large vat of Antidermis, a dozen special masks, and a large pile of various foreign technologies.
The Piraka discover that Antidermis can be used to enslave Rahkshi, but also that the Vault's secrets are far from resolved; the first Rahkshi Zaktan tames stumbles too close to the door of the Vault, and is incinerated while the Vault's riddle is relayed in a mysterious bodiless voice.
AkiriNuparu announces his intention to take Ko-Koro back from the forces of darkness, and unveils his engineers' latest military breakthrough: the Exo-Matoran.
Back in the Archipelago, Rora Yumiwa announces her acceptance (but also disapproval) of the Dastana's secession. Tensions appear to relax, but shortly after, the disgraced Vilda Toroshu is broken out of the Imperial prisons and the Dastana twins falsely implicate in her escape.
The disappearance of Po-Koro Sentinel outposts in the Dark Walk spur two groups to investigate the tunnels. They discover not only that the 'mythical' Artakha Bulls are very real, but that these powerful creatures have been corrupted by something darker. Out of the bowels of the earth a black ichor is seeping: Antidermis.
Hewkii finds himself no longer able to bear the pressures of leadership and steps down as Akiri of Po-Koro. Renaka, an ex-Guard with experience in government, is elected in his place. Her first major action in office is to adapt the telegraph system's technology into an internal messaging system for the Koro.
Echelon battles and defeats Joske Nimil in Ko-Wahi and uses his Komau to steal his knowledge and learn the truth behind Makuta's banishment. He then proceeds to kill Joske.