Samus Aran observes a battle between the Federation and Pirates on the surface of Norion.

The invasion on Norion was a full-scale military offensive by the Space Pirates against Base Sector Zero, a Galactic Federation military stronghold on the planet Norion. The Pirates sought to crash a Leviathan under their control onto the planet to begin the process of corrupting it and turning it into another Phaaze, as they had already begun to do with Bryyo, Elysia and their own homeworld. Samus Aran's mission to prevent the Leviathan impact is her first objective in Metroid Prime 3: Corruption. The invasion is named as such by the Lab Assistant that tends to Samus during her monthlong recovery following the event.


Space Pirates[]

A view of Norion.

After a disastrous mission on Aether, during which the Space Pirate mining facility was ravaged by both Samus and Dark Samus, the Space Pirates quickly gathered as much leftover Phazon as they could and brought it aboard their battleship, Colossus. However, they had also unwittingly collected the molecules of Dark Samus, who had been defeated by the real Samus and survived the destruction of Dark Aether. Dark Samus reformed herself by absorbing all Phazon aboard, and proceeded to eliminate a third of the Colossus's crew in minutes, brainwashing the rest to follow her in a quasi-cult.

Dark Samus went on a months-long journey shortly afterward, and returned with a massive Leviathan. She brought her followers to Phaaze, the origin point of all Phazon, using the Leviathan, and they began to mechanize the planet for the purposes of speeding up Leviathan production. To achieve this, the Pirates capitalized on an opportunity they learned of from agents within the Galactic Federation. Two months after the Aether mission, the Pirates attacked the G.F.S. Valhalla, an Olympus-class battleship on a training mission in the Klar Nebula, stealing all Energy Cells aboard, but more importantly its Aurora Unit: 313.

Returning to Phaaze, the Pirates corrupted 313 and established a symbiotic link between the Aurora Unit and the planet. This allowed Dark Samus to create and send Leviathans to planets at will. She first sent a Leviathan to the Pirate Homeworld, giving the Space Pirates there an organism rich in Phazon, that they could use to build a massive army. However, Aurora Unit 217 on SkyTown, Elysia detected the impact and traced its origins to the planet Phaaze. Before it could report its findings, Dark Samus sent a corruption virus through the entire Aurora Unit network via 313, forcing the Federation to disable it.

Once more Leviathans had matured, Dark Samus launched them at all three planets in the Federation Solar System: Bryyo, Elysia and Norion. Those sent to the former two planets impacted successfully, while the Seed intended for Norion was sent last. Norion would be the most difficult target, as it was the home base of the Federation Fleet. Dark Samus and Meta Ridley were both present on Norion to oversee the impact.

Galactic Federation[]

The Galactic Federation was able to quickly devise a vaccine to cure the Aurora Units of the virus before they would be unable to reverse the damage. While most of the units had been healed, a few remained infected, and the Federation hired Bounty Hunters to deliver the vaccine to these units.

Fleet Admiral Castor Dane summoned four Hunters to the G.F.S. Olympus Ready Room: Samus Aran, Rundas, Ghor and Gandrayda, and tasked them with delivering the vaccine to the remaining AUs. He noted that with the network offline, the Federation was vulnerable to attack. Almost by chance, Aurora Unit 242 proclaimed condition red, as a Space Pirate attack on Base Sector Zero was detected. Dane realized they were targeting the planetary defense system, and ordered the four Hunters to assist the ground troops in repelling the attack.


Samus fights a Pirate Aerotrooper on Cargo Dock A.

Landing on Docking Hub Alpha, Samus was alerted to the invasion by a Federation Marine who told her that the Pirates had disabled the three Fedtech Plasma Generators that power the planetary Defense Cannon. Samus rushed to restore Generators A and C, battling hordes of Space Pirates along the way, while Rundas reactivated Generator B for her.

In Generator A, Samus witnessed Gandrayda impersonating Pirate Militia, before flirtatiously leaving Samus to reactivate the Generator as "machines aren't my thing".

Samus battles Meta Ridley.

While exploring, Samus witnessed Meta Ridley flying over the base, and was later trapped by him in a Morph Ball tunnel. As she was reactivating Generator C, Ridley ambushed her and sent the both of them falling down an exhaust shaft. Samus defeated Ridley before falling to the bottom, and was rescued by Rundas, who left her to reactivate Generator C.

After Generator C was reactivated, Samus was alerted to the coming Leviathan by Dane. With no time to lose, Samus raced to the Control Tower, barely making it to meet the Hunters. At the top, they began the process of restoring the Defense Cannon, when Dark Samus appeared through the window. She proceeded to unleash a massive blast of Phazon toward the four Hunters, grievously wounding them. Samus used the last ounce of her strength to fully activate the cannon before losing consciousness.


Rundas, Ghor and Gandrayda awoke from their comas within a few weeks, while it took Samus an entire month to awaken from hers. The Galactic Federation discovered that as a result of Dark Samus's attack, the four Hunters were now generating Phazon within their bodies. This corruption was initially assumed to be benign, and they took advantage of this by installing Phazon Enhancement Devices onto the Hunters so that they could exploit their Phazon. Samus awoke to find that the Federation had created the PED Suit by placing the PED into her Chozo armor.

Upon meeting with Aurora Unit 242, Samus learned that Rundas, Ghor and Gandrayda had been sent to investigate the Leviathans on Bryyo, Elysia and the Pirate Homeworld, but contact with all of them had been lost. Samus was tasked with finishing their missions and destroying each Leviathan Seed. She discovered that their corruption was actually a slow-acting poison: remaining in Hypermode, a state of power that Samus achieves by tapping into her Phazon, for too long could cause her to succumb to Terminal Corruption, and fall under Dark Samus's control. Samus discovered that this was the fate of the other Hunters, and was forced to kill each of them.

Although Norion was spared a devastating end, it would be some time before it fully recovered from the assault. One month after the invasion, maintenance is seen to still be underway. The entirety of the sector leading to Generator B was still overrun by spent Phazon, where none of the troopers were willing to go. Many rooms that Samus had entered previously were now blocked by marines due to repairs. Samus can enter Generator B and defeat a Metroid Hatcher to obtain Energy Cell ID: WI-7823I-3.

Eventually, Samus would venture to Phaaze and confront Dark Samus and Aurora Unit 313 for the final time, destroying both them, and Phazon once and for all.