|“||It's a place like Tourian, where we propagate and raise Metroids.||„|
Sector Zero (セクターZERO Sekutā Zero ) was a vastly unexplored area of the Galactic Federation's BOTTLE SHIP. Its entrance could be reached through an elevator in the Cryosphere. Samus never entered the sector itself due to its destruction at the hands of Adam Malkovich.
Sector Zero contained Unfreezable Metroids as well as MB's original body within the Section 4 Gravity Block. MB's new android body informed Samus about it while she was posing as Madeline Bergman and sent Samus on her way to the sector, but intentionally withheld the crucial information concerning the Metroids' invulnerability to the Ice Beam in the hopes of eliminating her.
Upon Samus's arrival at the entrance, she is surprised by the sudden appearance of a Baby Metroid that reminded her of her hatchling. Deciding to kill it, she is suddenly shot in the back and collapsed to the floor, unable to maintain her Power Suit. The Metroid is shot and killed before it can attack her.
Her shooter is revealed to be Adam, who explains that she shot her to prevent her from walking into a trap. He also reveals that, despite the threats waiting inside, he intends to sufficiently damage the sector's interior in order to trigger both its detachment from the BOTTLE SHIP and its self-destruct mechanism, at the cost of his life. He proceeds into the sector, preventing Samus from following or stopping him, and moments later, Sector Zero begins to separate from the BOTTLE SHIP. Samus escapes the vicinity before the rest of the entrance falls off. Exposure to the vacuum of space forces her to activate her Gravity Feature, thus helping her flee from the breaking portions before time runs out. Super Zebesians are present in the area to intervene as she escaped, likely sent by MB.
If Samus returns to the corridor leading to the Sector's entrance, a large indestructible hatch will block the way prior to the detached sector. A sad musical theme played during these later visits in reference to Adam's death.
- Base Sector Zero is a similarly named area explored on Norion, which also serves as the Galactic Federation Marine Corps' home base.
- MB's statement that Sector Zero is a "place like Tourian" has led to speculation that it is a faithful recreation of the Space Pirate base from Zebes. The Galactic Federation is known to have blueprints for a Tourian-like base at some point in the past. These blueprints, simply known as "Future Aurora Complex", are shown in the third of Metroid Prime 3: Corruption 's preview trailers.
- The Restricted Laboratory from Metroid Fusion plays a similar role to Sector Zero: Metroids are being raised, both stations have a fail-safe protocol leading to their detachment and destruction if they sustain too much damage, and both stations are detached and destroyed by individuals other than Samus.
- It appears that at least one unfreezable Metroid escaped from Sector Zero and made it into the Cryosphere, as evidenced by a dead Gigafraug present in a room of the area that exhibits signs of Metroid predation. Additionally, when Adam explains to Samus the existence of the modified creatures, a flashback to the dead Gigafraug is shown prior to the scene cutting to an unfreezable Metroid breaking its container.
- If Samus attempts to reach a detached section of the sector during the escape by Space Jumping, she will automatically fall into the abyss of space and cause a Game Over.