E4M1: Hell Beneath (Doom)

E4M1: Hell Beneath is the first map of Thy Flesh Consumed in Doom. It was designed by American McGee and uses the music track "Sign of Evil." In the Doom Classic port, it has a par time of 2:45.

On Ultra-Violence, it is believed to be one of the hardest levels not only of the episode but also in the entire Doom series. On this difficulty, there are no medikits or stimpacks; any additional health is limited to nine health bonuses, and there is only one piece of green armor. The easier difficulties have four medikits, two of which are available through a secret.

Overview
The map title comes from Proverb 15:24: "The way of life is above to the wise, that he may depart from hell beneath."

Essentials
From the start (A), go forward (to the shotgun) then to the left, round the nukage pool, past the red door (B), then right and flip the switch (C) at the other end of the gallery. The marble wall blocking the short passage (D) to the right from the start will lower. Go back round the nukage pool and through the passage to another similar area. Follow the walkway to the right until you see an entrance (E) to the building in the center. Jump down into the nukage moat and go through the entrance. Walk up the stairs, turn left and pick up the red skull key (F). Go back downstairs to the room with a window. The raised floor in front of the window (G) is a lift. Ride it up and jump back to the walkway around the area, go through the passage (D), then around the nukage and through the red-key door (B), make your way around the rectangual structure occupying the back part of the room and pick the blue skull key in the niche (H). Go out of the room, follow the walkway to the blue-key door (I), open it and step on the white pad with a pentagram on it (J) in the room behind the blue door.

Secrets

 * 1) Drop into the nukage pool ahead of you at the start of the level. Press the use key on the end of the platform to the right to lower it, exposing a hidden tunnel with a rocket launcher at its end. Open the wall to the left of the rocket launcher to reveal a room (sector 69) with a pair of teleporters.  Each takes you to a corresponding ledge near the level's beginning. These ledges contain a medikit each on Hurt Me Plenty or lower difficulty.
 * 2) In the room behind the red door, make your way left around the rectangular structure and press the use key on the torch. This lowers the rectangular structure, uncovering a hidden "NIИ" logo. The area surrounding the "NIИ" letters is tagged as a secret. (sector 30) Note that the letters themselves are not tagged as secret, so this secret may be a bit tricky to register. Pressing "use" unleashes four barons. Walking across the "upper" side (closest to the room entrance) of the logo causes the walls to raise up, blocking the entrance to the room. The wall blocking the entrance has a switch to lower it. The logo is not present in console versions of Doom that feature this map, probably due to trademark concerns.

Bugs
There is a small Hall of mirrors effect visible at the top of the inside of the red door frame due to a missing upper texture, though it is barely noticeable in the darkness.

Current records
The Compet-N records for the map are:

The data was last verified in its entirety on April 5, 2013.

Inspiration and development
The "NIИ" logo is a reference to Nine Inch Nails, the American industrial rock band. Also, id Software's next game, Quake, would feature sound and music by the band's frontman, Trent Reznor.

Trivia

 * It is the smallest level in Ultimate Doom.
 * Teleport destinations are usually marked by the "crushed gibs" sprite.