- This level occupies the map slot MAP25. For other maps which occupy this slot, see Category:MAP25.
- Letters in italics refer to marked spots on the map. Sector numbers in boldface are secrets which count toward the end-of-level tally.
- 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.
- 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).
- 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.
- 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).
- 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).
- 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.
- 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.
- See secret #7 (sector 244).
- 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.
- 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.
- 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).
- 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).
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.
The Compet-N records for the map are:
|UV speed||00:23||Adam Hegyi||2002-02-28||mm25-023.zip|
|NM speed||00:39||Casey Alvis||2004-01-31||mm25n039.zip|
|UV max||06:04||Casey Alvis||2002-12-05||mm25-604.zip|
|UV -fast||08:19||Casey Alvis||2002-05-04||mm25f819.zip|
|UV -respawn||06:03||Casey Alvis||2002-05-14||mm25r603.zip|
|UV pacifist||00:29||Oyvind Stenhaug||2003-01-13||mm25p029.zip|
|Monsters||ITYTD and HNTR||HMP||UV and NM|
|Barons of hell||1||1||2|
|Weapons||ITYTD and HNTR||HMP||UV and NM|
|Ammunition||ITYTD and HNTR||HMP||UV and NM|
|Powerups||ITYTD and HNTR||HMP||UV and NM|
|Keys||ITYTD and HNTR||HMP||UV and NM|
- This level was one of the earliest two, complete levels to be submitted, along with MAP16: Stoned.
- This level share with Heretic level E3M2:The Cesspool.
- Memento Mori Infopack. William Sullivan and Kurt Schmid (author of MAP16: Stoned) are named "Fastest Guys" in the credits for sending "the first complete levels."