Plexal Basement

Plexal Basement is an area in B3313.

Description
The main section is made out of green walls and has a checkerboard floor. It has several doors leading to side rooms. It also has a hallways with a unique, red-black checkerboard floor and walls, with double doors at both ends. There is also a pipe in one of the corners, which, when approached, floods the whole area, with no means to escape except for some paintings out in the open.

With the usage of the Vanish Cap, the player can bypass the grid on one of the walls, reaching the back side, which also lets them access the orange section. This is structurally heavily similar to the Vanilla Basement, with its main hallways also having green walls with a polka-dotted floor. Most of the paintings and doors are completely blocked here.

Origins
The area's layout is mainly an original creation, although heavily inspired by the vanilla Super Mario 64's rooms, and textures are mostly taken from its beta versions. The red-black checkerboard texture originates from one of Greenio's videos.

The music is a variation of the "Inside Castle" theme from the same game's OST, with a different instrument, and several missing parts. Alternatively, if entered from the Orange Hall's window, the music playing is the "Haunted House" theme from the same game's OST.

Leading here

 * Orange Hall: Go through the window on the left. (This leads to the flooded state of the area.)

Leading away

 * Bowser in the Dark World: In the main section's front side, go through the single door to the left of the Lethal Lava Land painting, then the key door to the right, and finally jump into the hole in front of the Bowser painting. Alternatively, in the back side, jump into the hole to the right of the grid.
 * Castle Grounds: In the main room's front side, swim down the tunnel in the floor and then through the hole.
 * Cave City: In the orange section's main room, go through the bricked double door, and then jump into the hole.
 * Desert Maze: In the main section's front side, go through the door with the number 2 on it, on the wall opposite to the Lethal Lava Land painting, and then through the hole.
 * Flooded Town: In the main section's front side, go through the Wet-Dry World painting.
 * Dry Town: In the main section's front side, go through the Wet-Dry World painting after activating the pipe trap.
 * Sandy Skyloft: In the orange section's hallways, go through the painting of the pyramids.
 * Shifted Sand Land: In the main section's front side, go through the painting of the blocky pyramid.
 * Tiny-Huge Island (beta): In the main section's front side, go through the door with the number 2 on it, on the wall next to the hallway with the main grid at the end of it, and then through the painting of Tiny-Huge Island.
 * Vanilla Basement: In the main section's front side, go through the double door in front of the room with the red-black checkered floor, next to the blue flames.

Two-way

 * Beta Lobby D: Go through the key door, and then through the next double door up ahead.
 * Crescent Castle: In the orange section's main room, go through the double door with the crescent above it.
 * Orange Hall: In the main section's front side, go through the double door at the end of the room with the red-black checkered floor.
 * Plexal Lobby: In the orange section's hallways, go through the double door with the Bowser painting above it.
 * Silent Hall: In the main section's front side, go through the single door to the left of the Lethal Lava Land painting, and then the double door up ahead.
 * 4th Floor (Final): In the main section's back side, go through the grid with the pipe behind it, and then jump into that pipe, using the Vanish Cap.

Trivia

 * Before v0.7, the painting leading to Vanish Cap within the Plexus could be found here instead of in the Silent Hall, as that area didn't exist yet.
 * The idea for a flooded basement when the pipe trap is active appears to originate from Greenio's 'Promo show' video.