The Sub-Zero Containment is a room on the Main Deck of the BSL Station in Metroid Fusion. As its name implies, it has a sub-zero temperature, meaning that Samus Aran will constantly take damage if she has not obtained the Varia Suit.
This room is notable for containing the Ridley clone's corpse from Metroid: Other M, preserved in ice, that Samus can see when she enters the room (but she cannot touch it as there is a gate in front of her). It was presumably placed there by corrupt Galactic Federation members (likely those behind the BOTTLE SHIP). She is never required to see Ridley beforehand, but after Nettori begins to choke the activity of the Reactor Silo, Samus is forced to take an alternate route to her gunship. Along the way, she will drop into the chamber from the other side, and witness the corpse's eyes glow before a large X Parasite (more specifically, an unshielded Core-X) floats out of its chest, resulting in the body collapsing in front of her. This X would travel to Sector 1 and become Neo-Ridley, a boss that Samus had to fight. To escape the room, there is a Pit Block in the floor just under Ridley's remains.
- The Ridley clone's corpse uses the same sprite as the original Ridley for his final appearance in Super Metroid. Neo-Ridley has completely diferent sprites.
- Interestingly, this room will damage Samus much more slowly that the sub-zero areas of Sector 5, likely to make players comfortable enough to walk forward and see the frozen Ridley corpse, and because the damage is not meant to prevent Sequence Breaking.