MAP25: Cesspool (Memento Mori)

MAP25: Cesspool is the twenty-fifth level of Memento Mori. It was designed by William Sullivan and uses the music track "Slipper" by Mark Klem. It makes extensive use of the deep water effect.

Essentials
You need only one key to exit (the red or the yellow key). However, 100% kills requires both keys.

You start in a room with four teleporter pads. Open the door ahead and enter a blue-floored room with a pair of large doors and a pair of red buttons between them, which are switches. Take out the chaingunners in this room, if any. From here, you need to get either key to progress the level.

To get the red key, look at the north row of blue "split pillars" and find the one that is second from the right. On Hey, not too rough and below, an arrow of health bonuses points to it. Push on it, and the bottom half of the pillar will lower. Open the wall behind it for a plasma gun (on Hurt me plenty and below), then lower the back wall of this alcove. It is a platform, so ride it up to the red key.

To get the yellow key, flip the right switch in the middle to open the southern door. Follow the passage around to a door and a pair of switches. Shoot the northern switch to open the door. Drop into the blood (it is non-damaging), then into the blood pit below, where you can get the yellow key. Look for the brighter spot on the northern ledge and press use in front of it to lower it to the floor. Ride it up, jump to the higher blood pool, then lower the western edge of the pier to ride it back up.

Once either is done, backtrack to the blue-floored room just after the starting room, and flip the left switch in the middle to open the northern door. You may wish to access secret #9 first to get a radiation suit - it will come in handy soon. Follow the passage round to a door and shoot the southern switch to open it. You are now overlooking a slime pit. Unlike the blood pit in the south, this one is a damaging floor, and a 20% damage type to boot. Make a dash for the hole in the windows at the far end, avoiding the spectres in the pit on higher difficulties.

You will end up at a deep sludge-filled corridor. Find the platform and kill the imps and revenants (if any) on the platform. use the computer terminal that matches the colour of the key you have. Refrain from using the terminals at the side unless you are pursuing 100% kills - these open traps in front of them with former humans and no items. Each terminal will open a wall behind you to a new passageway. Go through the passageway and be sure to enter any one side room, kill the shotgun guy or two inside and press use on the computer panel directly ahead. This opens up at least one of the exit teleporters.

Continue up the stairs and kill the arachnotron waiting there (on Hurt me plenty and above). Position yourself so that the enemies in the large alcove ahead will infight with the spiderdemon. The higher the difficulty level, the easier your task is here. Once the spiderdemon is dead, drop into its pit and clear out the opposite large alcove.

As you continue forward up the steps, you will encounter two Hell knights and on Hurt me plenty and above, a pair of cacodemons. Imps will also begin teleporting onto the northern teleporter pad. Ignore the southern teleporter pad - it takes you to the start of the level. The imps should not be too much of a problem, and can even be ignored with some speed. On Ultra-Violence and above, you might want to exit the level before the last two monsters in the teleport trap (an arch-vile and a revenant) teleport in, since there isn't much cover from their attacks in here.

At least one of the four teleporters ahead should be unblocked. Step into any of the four teleporters to exit the level.

Secrets

 * 1) In the starting area, press upon the southeastern computer terminal to reveal a switch. Since you cannot open it again, quickly shoot this switch before it closes to open a secret alcove (sector 134) containing six boxes of shells, two boxes of ammo, two boxes of rockets and a megasphere. It is best to save this for after you obtain secrets #2-6.
 * 2) The next five secrets can only be accessed for the first 30 seconds of the level, so time is of the essence. First, in the room after the starting area, enter the southwestern compartment with the blue armor and kill the sergeant at the bottom. Enter the space he was on (sector 9).
 * 3) After registering secret #2, get into the southern compartment with the soul sphere and kill the imp on medium and hard skill levels and enter the place he was on (sector 11) or simply grab the box of ammo on easy skills.
 * 4) Then, head into the northeastern compartment with the computer map (and kill the sergeant on hard skills). Enter the compartment to the north (sector 18) (to grab the bulk cell on easy).
 * 5) After that, enter the northern compartment with the backpack, the bullet box, the shell box and the rocket box and head down to find a sergeant. Kill him and enter the space he was in (sector 17).
 * 6) Finally, go in the compartment in the northwest with the super shotgun and take the elevator down to find an imp (not on easy). Kill him and step into the sector to the north (sector 16). If you are fast enough, you can obtain all five of these secrets before the doors close, permanently blocking access. If you are in a compartment when the doors close, just open the one you are behind to get out.
 * 7) Also in the room after the starting area is a compartment with a radiation suit in the southeast. You can enter this and take it down before the doors close, leading to a secret room (sector 245) containing (a shell box on easy, an imp on hard and) four radiation suits. This actually consists of two sectors, both of which are marked secret. Alternatively, you can get here through secret #9.
 * 8) See secret #7 (sector 244).
 * 9) While standing in any of curved hallways in the east, shoot at the light poles through the hole between the hallways. This will open a compartment (sector 61) in the southern one containing one (two on hard) imp(, a chaingunner on medium and hard skills) and a blue skull key. Walk toward it and you will be teleported into secrets #7 and #8.
 * 10) In the northern, curved hallway in the east, open the window. This will also open a compartment (sector 243) behind you containing one (three on hard) chaingunner, an imp, four (two on easy) lost souls and a rocket launcher. On Hurt Me Plenty or lower, this will also contain a bulk cell, a chainsaw, a berserk pack and a box of shells.
 * 11) After obtaining the yellow and the red skull keys, ascend the stairs in the northern hallway mentioned in secret #10. Cross the nukage to the west until you arrive in a sewer. Go south and enter the terminal area in the east. Use the yellow skull terminal to open the southern hallway in the sewer behind you. Enter the western door in this hallway; the computer terminal right in front of you opens the northwestern map exit alcove later in the map. Use its western side to raise a wall to the west, revealing a box of rockets (sector 242).
 * 12) Return to the terminal area east of the sewer mentioned in secret #11. Use the red skull terminal to open the northern hallway in the sewer behind you. Similar to secret #11, enter the western door in this hallway; the computer terminal right in front of you opens the northern map exit alcove later in the map. Use its western side to raise a wall to the west, revealing a soul sphere (sector 247).

Bugs
Linedefs 314, 316, 320 and 322 are flagged as lower unpegged. As a result, since the doors in the blue room are lowered to the level of a floor deeper than the surrounding sectors, opening the doors causes the TEKLITE texture on the inside of the "door pits" to scroll upwards as the doors open. Whether this is intentional or not is unknown.

Routes and tricks
This map is one of the few maps in Memento Mori that can be completed in under a minute, and one of the few that can be finished in less than 30 seconds. The required path through this map is quite short, but if you are speeding through the level, be prepared to take a lot of damage in the process.

Enemies cannot see into or out of sectors where the deep water effect is used, so in many places in this level, you can perform endless sneak attacks on enemies from inside these sectors, as well as on enemies inside these sectors from outside of them. In particular, the Spider Mastermind at the end of this level is unusually easy; because she cannot see out of the deep water sector she is in, you can stand on the stairway and fire upon her without her ever shooting back.

A death slide can be performed on this level by walking into any of the exit alcoves, prior to opening them, and letting an enemy's projectile kill you. This will push your corpse into the teleporter and end the level.

When performing UV max runs of this level, the preferred method to enter secrets #7 and #8 is to do so through secret #9. That way, you can enter secrets #2-6 during the level's first 30 seconds, and then proceed through the level from there.

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

The data was last verified in its entirety on July 4, 2020.

Player spawns
This level contains four spawn points:
 * 1) facing west. (thing 145)
 * 2) facing east. (thing 149)
 * 3) facing south. (thing 150)
 * 4) facing east. (thing 155)

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

Trivia

 * This level was one of the earliest two, complete levels to be submitted, along with MAP16: Stoned.