Metroid Fusion

Metroid Story chronology Main series in bold , remakes in parentheses Metroid manga series Metroid ( Zero Mission ) Metroid Prime Metroid Prime Hunters Metroid Prime 2: Echoes Metroid Prime 3: Corruption Metroid Prime: Federation Force Metroid II: Return of Samus ( Samus Returns ) Super Metroid Metroid: Other M Metroid Prime 4: Beyond Metroid Fusion Metroid Dread v t e Bounty hunter Samus Aran explores the surface of the planet SR388 with a survey crew from Biologic Space Laboratories (BSL). She is attacked by parasitic organisms known as X. On returning to the BSL station, Samus loses consciousness, and her ship crashes. The BSL ship she was escorting recovers her body and transfers it to the Galactic Federation for medical treatment, who discover that the X has infected Samus' central nervous system .

They cure her with a vaccine made from cells taken from the infant Metroid that Samus adopted on SR388. : 88 The vaccine gives her the ability to absorb the X nuclei for nourishment, : 8 but burdens her with the Metroids' vulnerability to cold. Portions of Samus's infected Power Suit are sent to the BSL station for examination, although the suit was too integrated with her body to remove entirely during surgery. When Samus recovers consciousness, she is sent to investigate an explosion at the BSL station.

The mission is overseen by her new gunship's computer, whom Samus nicknames "Adam" after her former commanding officer , Adam Malkovich. : 13 Samus learns that the X parasites can replicate their hosts' appearances, and that the X have infected the station with the help of the SA-X , an X parasite mimicking Samus at full power. Samus avoids the SA-X and explores the space station, : 98, 107 defeating larger creatures infected by the X to recover her abilities. She discovers a restricted lab containing Metroids, and the SA-X sets off the labs' auto-destruct sequence while attacking the released Metroids, who also devour the SA-X.

Samus escapes, but the lab is destroyed. : 135–136 The computer berates Samus for ignoring orders and admits that the Federation was secretly using the lab to breed Metroids. It also reveals that the SA-X has asexually reproduced , subsequently cloning itself. The computer advises Samus to leave the station.

On her way to her ship, the computer orders Samus to leave the rest of the investigation to the Federation, which plans to capture SA-X for military purposes. Knowing that the X would only infect the arriving Federation troops and absorb their spacefaring knowledge to conquer the universe, Samus states her intention to destroy the station. Although the computer initially intends to stop Samus, she calls it "Adam", and reveals that Adam died saving her life. The computer suggests that she should alter the station's propulsion to intercept with SR388 and destroy the planet along with all X populations.

Samus realizes that the computer is the consciousness of Adam, uploaded after his death. En route to initiate the propulsion sequence, an SA-X confronts Samus, who defeats it and sets the BSL station on a collision course with SR388. As Samus prepares to leave, she is attacked by an Omega Metroid. The SA-X appears and attacks it, but is destroyed; Samus absorbs its nucleus and uses her newly restored Ice Beam to destroy the Omega Metroid.

: 141–143 Her ship arrives, piloted by creatures Samus rescued from the station's Habitation Deck. They escape before the station crashes into the planet, destroying it.