In both games, this is a corridor connecting between the two shafts on the upper right side of Kraid's Lair.
In Metroid, this room is optional and does not need to be explored, seeing as it does not lead to Kraid or any expansions or power-ups. It is one of three identical corridors between the "apex shaft" and "Zeela-infested shaft", containing the same enemies and layout. The room is constructed from blue bricks and tiles, with three pits of acid in the floor and two Air Holes in the floor, and three silver pillars near the left side.
In Zero Mission, the room's appearance has been changed and it is now different from the other two corridors above and below it. Its ceiling and floor are now made of solid material with various Chozo symbols etched into them. Ruined walls with cracks can be seen in the background. It is about the same length as it was in the original Metroid. The acid pits have been consolidated into one large pit near the right side, with the ground on the left having a slight divot in the center.
An ancient Chozo machine is found here. Once Samus enters the room, the door locks behind her. She can morph into a slot within the machine, and the resulting surge of electricity reactivates all zip lines in Kraid, including one in this room. The switch to bring the zip line over to the left is found directly above the machine's slot for the Morph Ball. As Samus rides the zip line, she will come in contact with an Energy Tank atop a pedestal that is suspended in the acid, and automatically collect it. Directly to the left of the pedestal, Geegas can be found spawning two at a time from the acid. The Energy Tank offers Samus a last minute energy boost ahead of her battle with the Acid Worm.
- "Zeela-infested shaft" (via Blue Door)
- "Apex launcher shaft" (Metroid, via Blue Door)
- Save Room 2 (Zero Mission, via Blue Door)
- Geegas spawned 2 at a time from the acid
- Energy Tank (Zero Mission)
- See above.
- If a Low Percent Run is being performed and Samus does not wish to collect the Energy Tank, she can Turbo Bomb up to the zip line handle and ride it across. This way, she will not touch the Energy Tank and pick it up.
- 077 TURN ON THE POWER (pg. 45)
- "An ancient Chozo machine sits at the left edge of a lava [sic] pool. Jump onto the machine then roll into Morph Ball form to activate it. Every red light in the lair's ceiling will illuminate, indicating that the area's sliding mechanisms are up and running."
- 078 energy tank (pg. 45)
- "After you activate the machine, fire at the red light on the ceiling to call the carrier. The apparatus will slide to the left side of the lava [sic] pool. Use it to cross the pool, collecting an Energy Tank as you go."
- 15% walk-through STEP 13 (pg. 101)
- "Advance to the lair's upper-right section and activate the machine that will allow you to slide along the ceiling rails."
- 15% walk-through STEP 14 - OPTIONAL (pg. 101)
- "Immediately after you activate the ceiling conveyer, fire at the red flashing light directly above you to call the apparatus, then use it to slide to the Energy Tank in the middle of the corridor."
- 15% walk-through STEP 15 (pg. 101)
- "If you choose not to collect the Energy Tank, you can avoid it by propelling yourself in Morph Ball form up to the conveyor. You'll slide over the tank without grabbing it."
The guide erroneously refers to the acid in this room as lava.