The main shaft is an area of NEST.
The main shaft act as the central hub, separating the east and west area of the NEST as well as the main power source for it.
Resident Evil 2
Due to the missing main fuse on the breaker system, the power is not active in certain locations. Once the main fuse is found, the player can put it back on the breaker system to restore power.
After returning to this main shaft during scenario A with the G-Virus, Ada will appear on the platform. Ada points her gun toward Leon, asking him to give her the G-virus. All of a sudden, Annette shots Ada from behind before falling unconscious on the platform. At this time, Ada was weakening by the gun shot and was about to fall from platform, though Leon managed to grab her by the hand. Despite Leon effort trying to save her, Ada proceeds to let go of his grips and falls to the death. Leon then collapse in despair and throw the G-virus away from the platform afterward.
In Claire's scenario B, the player will find Annette lying here on the platform towards the west passage entry with Sherry beside her. Annette would proceeds to speak her last words before dying at that moment. Assuming Claire's control, the player can grab the Master key afterward and exit the main shaft.
This area is visited twice in the game.
In chapter 6, the Main shaft is only visited briefly after the T-00 chases Leon and Claire from the B4F turntable room. There is Sub Machinegun ammo next to the breaker system, and gold bars next to the door that leads to the B4F west area passage. Strangely, the cutscene in this area shows Leon and Claire running towards the B4F west area passage, but the next gameplay sequence shows them arriving at the A-2 Elevator in the B4F turntable room.
In chapter 7, the William Birkin boss battle happens in this room, the second, third and fourth forms of Birkin are fought in this place. In between his first mutation (from second form to third), an Evolved Licker will appear near the breaker system, there is also Sub Machinegun ammo and a Herb that can be picked up during this instance with the Licker.
Just like his fight in the Septic Tank, the battle sequence is heavily scripted and the player needs to wait for the William to be on his fourth form in order to end the fight. Some of William's attacks also feature QTEs again.
|Huge breaker system||A huge breaker system that regulates all the power in the lab. The main fuse has been removed and the power is not active in some area.|
|The huge breaker system (Once power is restored)||A huge breaker system that regulates all the power in the lab.|
|Ada's gun (Leon, scenario A)||It's Ada's gun. There are no rounds in the magazine.|
|Annette (Leon, scenario A)||What made her do that...!?|
|The gun on the floor (Claire, scenario B)||It's a gun. It's not loaded.|
|Annette (Claire, scenario B)||Her fever has subsided and she is resting as though asleep.|
|All exit except the B4F turntable access||There's no time to go back!|