In the time before time, before the Matoran lived on the island of Mata Nui, the great city of Metru Nui was their home. Six Matoran were transformed into Toa heroes to save the metropolis from a false leader and his Dark Hunter servants.
A thousand years before the Toa defended the island of Mata Nui from Makuta and the Bohrok Swarms, the city island of Metru Nui was a bustling metropolis. Its six districts boasted tall towers, intricate transportation chutes, great furnaces to make nearly anything, halls of wisdom, and large fields filled with artwork by master carvers. The skilled Matoran inhabitants were happy and prosperous, but that was about to change.
Six Matoran, unaware their lives were about to change, worked in different regions of the great city. Whenua was an archivist in Onu-Metru; Nokama was a respected teacher in Ga-Metru; Matau rode fast-moving vehicles in Le-Metru’s test track; Nuju pondered great thoughts from towers in crystalline Ko-Metru; master carver Onewa called Po-Metru home; and mask-maker Vakama worked near the furnaces in hot Ta-Metru. Each received a mysterious visit from the city’s lone Toa, Lhikan, along with a stone and instructions to visit Ga-Koro’s Great Temple.
Their transformation to Toa startled them all, but it came none too soon. Toa Lhikan was kidnapped in front of Vakama by two Dark Hunters. And as the Toa soon discovered, a voracious plant called the Morbuzakh was invading Ta-Koro and destroying vital equipment. Nothing appeared to stop the creeping vines, and many of the forges and furnaces of Ta-Koro were abandoned or destroyed.
But Toa Vakama had a vision: the Morbuzakh nearly destroying Metru Nui, but being beaten by a Great Kanoka Disk. His vision also showed six Matoran who could help the Toa find the disks. So began their quest for these Matoran, and the six Great Disks.
In the course of their search, the Toa discovered one of the Matoran was a traitor. But despite this, they all managed to find their Great Disks and use them to defeat the Morbuzakh. Thinking their perils had ended, the victorious Toa brought them to Turaga Dume in the great Coliseum at the center of the city.
To their immense surprise, instead of being hailed as heroes, the six were ridiculed by the city’s leader. Summoning a whirlwind and his mechanical Vahki enforcers, Dume imprisoned Onewa, Nuju and Whenua – but Vakama, Nokama and Matau escaped.
While on the run, Vakama discovered the Great Disks could be fused together to form a single Disk of Time. This was the key to what Turaga Dume had ordered of Vakama as a Matoran: create a Mask of Time. He put it aside when another vision showed him that Matoran were being put into canisters in Po-Metru. They set out for that district to find Lhikan, fighting their way past two Dark Hunters, the burly yet stupid Krekka and four-legged, sneaky Nidhiki. Matau’s newly-discovered mask power of shapeshifting helped them escape, and Nokama’s mask of translation let them befriend a herd of Kikanalo beasts.
Meanwhile, Onewa, Nuju and Whenua met a mysterious Turaga while in prison. He told them they must learn powers of cooperation to find their mask powers and escape. After false starts, the three Toa stumbled into their powers and gained confidence in their own abilities. When they escaped, they brought the Turaga with them.
In dark tunnels under Po-Metru, the two groups reunited. All were shocked to find their mysterious Turaga companion was none other than Lhikan, transformed from Toa into Turaga!
The tunnels held many spherical pods like those Vakama had seen in his visions. Opening one, they discovered the real Turaga Dume imprisoned. But who was running the city behind Dume’s mask?
Chased from the tunnels by Vahki enforcers, the group escaped into a strangely empty city. Where were the Matoran? The obvious destination was to confront the false Turaga Dume in the coliseum, so the Toa and Lhikan arrived just in time to see Matoran being ordered into more pods. Vahki took the pods and stored them under the coliseum.
Indignant, the Toa confronted Dume. But it wasn’t Dume. Removing his mask, the figure revealed it was actually Makuta!
Darkness engulfed the city as it quaked. The time of shadows had arrived, and the Great Spirit Mata Nui fell into a deep slumber. Unable to beat Makuta at the center of his power, the heroes and Lhikan escaped in a Vahki transport, grabbing six pods containing sleeping Matoran as they went. The Dark Hunters attacked, but were plucked away by a whirling maelstrom that was Makuta, who used the Hunters to increase his own power. The Toa drove their Vahki transport into the protodermis ocean to escape, but Makuta sped ahead of them to a cliff top in the angry silver sea.
During the escape, Vakama had fashioned the Disk of Time into a mask, the Vahi Mask of Time. This powerful and dangerous Kanohi mask allowed Vakama to slow time around Makuta, but Vakama’s control was uncertain and he became entangled in its effects. Only Turaga Lhikan was able to save the Toa – but at the cost of his own life. Vakama had enough time to finally discovere his own mask power – invisibility.
Vakama couldn’t defeat Makuta on his own. The dark being was about to put on the Vahi when Vakama flung a disk and the mask of time dropped into the sea. Dodging blasts, the Toa was nearly overwhelmed when his five fellow Toa arrived. Working in unison, the six Toa emprisoned Makuta in a hardened prison of solid protodermis.
Although Makuta was no longer an immediate threat, their perils were not over. More quakes shook the sea, and the small boat with its few pods of Matoran aboard headed for a small crack in a great barrier. Their discovery of a pristine jungle island provided only a brief rest, for they still had Matoran to rescue.
Little did the group know of the cataclysms that occurred elsewhere – Metru Nui fallen to ruin and shrouded in webs, islands broken and villages sunk, a great waterfall streaming into a cave unknown to even the Turaga.
But those adventures would await them and other Toa.