MAP23: Tombstone (The Plutonia Experiment)

MAP23: Tombstone is the twenty-third map of The Plutonia Experiment. It was designed by Milo Casali and uses the music track "Bye Bye American Pie" from Doom II (the same as Doom II's MAP23: Barrels o' Fun).

Essentials
The teleporter leading to the exit chamber is only locked by a red key, but the exit chamber also contains three barriers that need to be lowered by corresponding keyed switches around the map.

Blue Key and Switch
You begin in a circular room with two corridors out, and will immediately come under fire from numerous enemies from both sides. Take either corridor out, being careful of revenants in the niches behind you. Go to the back of the room and follow either corridor around to the north (they are part of the same central "oval corridor") to a door with white strips beside it.

As you enter this room, revenants will rise up on pillars around you. Dispatch them and move forward to another room with more enemies, and grab the blue key.

Return to the central oval corridor, and follow it around to a room in the south. Flip the switch with blue banners on the room's north wall. This unblocks one of the barriers in the exit chamber.

Yellow Key and Switch
Follow the central oval corridor to the northwest, and proceed through the passageway to a blue door. As you enter the next room, you will encounter some imps, a cacodemon and a pain elemental. A revenant also will rise out of the pillar in the room. Kill them all and proceed east to a blood-filled open area.

This area is infested with enemies, with demons and spectres on the ground, revenants on one platform, and a large number of shotgun guys on another platform. The blood here is damaging, unlike the start room, so stay on dry land. Prioritize the revenants, then the shotgunners or demons/spectres if possible.

Next, take the dry path in the southwest of the room. This will take you past a red-bannered switch (remember its position, you need to activate it later) to the shotgunners' platform. Flip the switch to lower a pillar blocking your access to the yellow key.

Backtrack, then take the path in the southeast of the room, and follow it to its end. There should be a switch on the northwest wall of the passageway's end chamber. Flip it to lower the platform, then ride it up to the yellow key.

Leave this room, and backtrack to the passageway with the blue door. Proceed down the stairs in the west of the passageway to the black-bannered switch (which actually is a yellow switch) and flip it. This unblocks one of the barriers in the exit chamber.

Red Key and Switch
Follow the central oval corridor to the south, find the room with the blue switch, and open the yellow door in the southeast corner. You will be in a corridor with a window overlooking the red key room. Kill any pain elementals you see, and proceed along the corridor to a large room filled with enemies. The blood here is non-damaging, so feel free to stand in it.

To unblock the corridor in the north, you need to flip a switch behind two large pillars in the south of the room. However, be careful - the moment you cross onto the dry land where the switch is, the two large pillars will lower, unleashing two arch-viles and six revenants. The room does not have much cover for evading the arch-viles' fire blasts, so get into the corridor that you used to enter this room fast. You will then be able to peek-a-boom the enemies from that spot safely.

When the coast is clear, move into the unblocked northern corridor, and follow it around to a path overlooking the red key room. Follow the path to near the edge, but do not drop in yet - as you approach, eight spectres will be released into the red key room, and you do not want to be stuck with them in the damaging blood. Dispose of them from high ground, then jump in and deal with a newly released mancubus. Grab the red key, then enter the teleporter next to it.

You will be back on the ledge that you were on before dropping into the red key room. Backtrack through the level to the red bannered switch (near the shotgunners' platform in the yellow key area) and flip the switch. Do be careful on the way there - two traps with revenants have opened near the blue-bannered switch room.

Exit
Follow the central oval corridor to the southwest. Open the blue door inside, deal with some cacodemons and pain elementals, and then open the red door at the end of the passageway. Enter the teleporter to be teleported to the exit chamber.

If you have done all the steps correctly, the exit teleporter should be completely accessible. (If it is blocked, you have forgotten to activate one of the keyed switches.) Step into the exit teleporter to end the level.

Secrets

 * 1) At the very beginning of the level, head straight forward until you hit a wall. Open it to get some rockets.
 * 2) From the level start, heading either east or west will take you to identical blood-floored rooms. In addition to this main passage running between the two, there are two additional narrow passages to the north and south. Go through the southern one (which is lined with armor bonuses). About halfway through you will see a section of the grey brick wall that lacks the green slime found on the surrounding walls. Open it to get some more rocket ammunition.
 * 3) There is a yellow door just northeast of the starting rooms. The wall next to it, like the previous two secrets, lacks the green slime the other walls have. There are even more rockets behind it, as well as a teleporter pad.
 * 4) Step onto the (fake) teleporter pad in secret #3 to lower a nearby column, revealing a megasphere.
 * 5) In the blood-floored room the red skull key is in, there is a dark passage off to the south, between two glowing skull decorations. Step onto the platform at the end of this passage and flip the switch to lower the lift to a hidden soul sphere.

Bugs

 * This level can not be played in deathmatch, because there are no deathmatch starts. This bug is not present in an alternate version of PLUTONIA.WAD found on GOG.com and a specific version of the id Anthology.

Current records
The Compet-N records for the map are: The data was last verified in its entirety on May 5, 2013.

Map data
* The vertex count without the effect of node building is 1682.