MAP27: Ruby Abyss (Community Chest 3)

MAP27: Ruby Abyss is the twenty-seventh map of Community Chest 3. It was designed by Eric Baker (The Green Herring), and was the author's first completed and published level. It uses the music track "Inferno's March," composed by Baker specifically for the map; the only other level in the megawad with this distinction is MAP15: Clash of Galaxies, by the same author.

It takes place inside of a large, red, rock cavern, where blood flows everywhere, with a blue and red energy pillar in the center. There are four distinct sections of the level which must be fought through; as each section is completed, the pillar rises to reveal a smaller pillar until the exit is opened.

Secrets

 * 1) In either one of the blood pools at the south the level, if you walk up to the southernmost corner furthest away from the center, you will be lifted out of the blood. Open the wall here to find an elevator leading to 62 health bonuses and a berserk pack. (sector 1295)
 * 2) At the north of the level, when you activate the first switch in the northeast, the switch that is revealed will have two columns of lights at either side instead of one each. Shoot this switch instead of pressing it, and the wall will open in the northeast of the blood well in the previous room to reveal 7 health bonuses, 16 shotgun shells, and a super shotgun. (sector 339)
 * 3) At the far east of the level, stand at the center south of the room and look out through the southwest window. At that spot, you will find an eye recessed in the wall. Shoot this eye, and return to the altar to find that the demonic face in the north has opened to reveal a teleporter. It will take you to one of the heavy weapon dudes' turrets at the south of the level, telefragging him. (sector 44) Continuously run forward to teleport to the other turrets and back to the east of the level, telefragging the rest of the heavy weapon dudes, and collecting two stimpacks, a medikit, 27 health bonuses, and megaarmor.
 * 4) At the entrance to the fortress in the west, there are two doors recessed in the wall at the west and east sides beyond the metal prongs. The easiest way to access them is by climbing through the windows above, standing on the prongs, and walking in their direction until you drop down in front of them. Open these doors to find switches; activate the switch, and leave the alcove to be teleported back to the room you dropped in from. When both switches are activated, the horned face to the west immediately in front of the door at the end of the central hall will open to reveal a teleporter. Enter it to be warped into the blood tunnel behind where player 1 starts the level, where you can obtain a megasphere. (sector 308) Run toward the bars behind the megasphere to be teleported back into the fortress.

Bugs
The ceiling of the doors leading into secret #1 (sectors 51 and 418) are eight map units under the floor.

When the walls open to reveal monsters in the north of the level after obtaining the yellow key, three of the linedefs under the rising wall in the southwest (linedefs 2435, 10648 and 10650) are set as lower unpegged. As a result, the textures on these linedefs move along with the wall.

When the pentagram stairs are built in the east, the sections of the bridge keep the blood flat until the stop moving, whereupon they instantly change to a metal flat. This also happens with the bridge built in the west, whose sectors keep the red rock flat until they stop moving, after which they immediately switch to red marble flats. This is due to a programming error in Boom's generalized linedefs, in which texture changes are called when the sector stops moving no matter which direction it is going.

Current records
The records for the map at the Doom Speed Demo Archive are:

The data was last verified in its entirety on January 13, 2022.

Player spawns
This level contains eight spawn points:
 * 1) facing south-west. (thing 692)
 * 2) facing north-west. (thing 693)
 * 3) facing north-east. (thing 694)
 * 4) facing south-east. (thing 695)
 * 5) facing south. (thing 699)
 * 6) facing west. (thing 729)
 * 7) facing north. (thing 755)
 * 8) facing east. (thing 781)

Things
This level contains the following numbers of things per skill level:

Inspiration and development
This level was started in January 2007 for a project that was never finished, with the working title of Matryoshka in reference to how the energy pillars in the center of the level rise to reveal smaller pillars in a similar fashion to s. The MAP27 slot was originally taken by Daniel Gimmer (Tormentor667) on December 11, 2006; on June 9, 2007, he switched to MAP06: Foregone Destruction. That same day, Baker, an external playtester for the project at the time, asked to take the MAP27 slot with the southern and northern sections of the level completed, and their request was granted. A beta of the level was sent to playtesters on July 7, 2007, having gained its final title by this time, and the level was completed and submitted on July 9, 2007.

The level contains a large number of impact-trigger switches, used in two puzzles and for one secret. This is because at the time the level was built, the author frequently played Duke Nukem 3D, in which buttons can be triggered by gunfire, a fact exploited for certain puzzles.

The music for this level was started on June 28, 2007 and completed the same day. It was later remixed by James Paddock (Jimmy) as "Inferno's March (Creepy Remix)."

The level originally did not end with a boss fight in the center; the player simply ran onto the central pillar to exit. However, players Brian Nesser (Anima Zero) and Richie Agnew agreed this was an anticlimax, and Nesser suggested the dual cyberdemon fight that appeared in the completed level.

Trivia
If you activate the noclip cheat, head out the eastern side of the level onto the red cliff and look at the wall, you will find a message reading "TGH says: Quit using noclip!" If you use noclip to go all the way to either end of the cliff at the west of the map, or all the way to the end of the tunnel behind secret #4, you will find a message that says, "You're not supposed to be here! -TGH" These are homages to professional, who is well known for hiding Easter egg messages in his levels, often accessible only by cheating, most notably in his levels for Duke Nukem 3D.