MAP31: Cyberden (The Plutonia Experiment)

MAP31: Cyberden is the first secret map of The Plutonia Experiment. It can be reached via MAP15. It was designed by Dario Casali and uses the music track "Sign Of Evil" from Doom. The map is named for the four Cyberdemons it contains. They start in visible but inaccessible cages where they can't be hurt by or attack the player; throughout the map they will be released. The pre-level text for this level states: ''You've found the second-hardest level we got. Hope you have a saved game a level or two previous. If not, be prepared to die aplenty. For master Marines only.''

Essentials
Four switches located around the map must be pressed to open the cages releasing the Cyberdemons. Each cage has a switch inside it and when all four are toggled, the yellow key in the center of the map becomes accessible and allows the player to exit. This is the only functioning exit in this level, which leads to the second secret map, MAP32: Go 2 It. There is no normal exit that leads to MAP16: The Omen, so if you previously chose to play this secret map, it'll be mandatory to play the other secret map as well.

Cyberdemon #1
You start in the middle of a large arena. Locate the sunken staircase in the ground in the northwest of the map and enter it. Turn right into a room with a chainsaw, then up a flight of stairs. Continue east through the large room until you reach a tan passageway. The passage will make 3 U-turns - first overlooking the central arena, a second shortly after and the third where the passage gets darker. Remember the two walls at the north side of the second U-turn and the southern wall of the third U-turn - they are impassable false walls, and knowing their position is the key to defusing a very nasty trap in the area ahead.

As you reach the end of the corridor, you will encounter 2 arch-viles, who will almost immediately teleport away. One will be behind each fake wall previously mentioned, and unless you know where they are, you are in trouble. Immediately turn around, face the southern wall of the third U-turn, and fire rockets into the fake wall until you hear the arch-vile's death sound. Backtrack a little, face the north side of the second U-turn, and repeat with the second arch-vile.

Return to the room at the end of the corridor, and flip the switch. A corner of the room will lower, with some goodies, but this will also lower the first cyberdemon. Backtrack, and dispose of the hell knights that have been revealed in the previous big room. Return to the sunken staircase, enter the arena, and dispose of the first cyberdemon.

Head to the north structure where the cyberdemon came from. Flip the switch on the left to open the door, then flip the switch in the room ahead.

Cyberdemon #2
Return to the sunken staircase and the large room. A new door has opened in the northeast of the room, with a new large switch and some demons. Hit the large switch, return to the arena and defeat the second cyberdemon.

Head to the eastern structure where the cyberdemon came from. Flip the switches on either side to unlock the door. When you hit the switch in the end of the room, the floor will lower, and two hell knights (on Hurt me plenty and lower) or two barons of hell will ambush you from below the "pillars" in the room. Flip the switch in the southern alcove, then exit as the floor rises up.

Cyberdemon #3
Return to the room with the second large switch. A door in the west wall of the room has opened. Enter, wary of a chaingunner ambush, then flip the large switch in this room. Once again, return to the arena and defeat the third cyberdemon.

Head to the western structure where the cyberdemon came from. Flip the left switch to open the door, and deal with the mancubii inside. Only when they are dead do you flip the right switch (which raises a wall hiding the switch in the back of the room ahead), dash forward, and flip the switch. Use speed - the floor does 20% damage!

Cyberdemon #4
Return to the sunken staircase and the large room. A door on the west wall of the large room has opened. Follow it into a dark staircase, leading to another chamber with a large switch. Enter, once again being wary of a chaingunner ambush, then flip the large switch. Return to the arena and defeat the fourth, and final, cyberdemon.

Head to the southern structure where the cyberdemon came from. Flip the switches on either side of the door to unlock it. You will enter a marble room with a small pool of blood in its middle. Take out the chaingunners, and be mindful of two revenants in the northern corners of the room, which cannot be seen from the entrance. Climb the stairs and head to the back of the room, which is a U-shaped corridor. Proceed to the eastern arm of the U to flip a switch, but as you do so, a teleport trap will activate, teleporting up to 15 demons into the room.

Finale
Flip the switches next to the door you used to enter the marble room, and head back to the arena. A spiral staircase has appeared around the central pillar where the yellow key was. Ascend the staircase and collect the yellow key.

You can now unlock the yellow door in the southwest of the match, which apparently contains a teleporter. When stepped on, it turns out to be a fake, and lowers the walls in the room to reveal some boxes of rockets. However, use extreme caution when stepping out of this room and back into the central arena - two traps in the east and west walls have opened, releasing 12 (on Hey, not too rough or below), 18 (Hurt me plenty), or 26 (on Ultra-Violence or higher) revenants. Use the central pillar in the arena to dodge the homing missiles, herd them up and return fire with the rocket launcher or BFG 9000.

Head to the western trap and flip the switch in the back of the wall. This reveals the exit chamber in the southeast of the arena. Step into the exit teleporter to end the level.

Secrets

 * 1) In the green marble wall at the south end of the level, climb the stairs and make your way left along the narrow corridor in the back of the room. Approaching the skull switch here opens a room back on the lower floor. There's half of a lion-face on one of the walls in the new room; open it to reveal a teleporter to a secret area.

Current records
The Compet-N records for the map are: The data was last verified in its entirety on February 4, 2013.

Map data
* The vertex count without the effect of node building is 932.