E4M6: Sanctuary of Filth (No End In Sight)

E4M6: Sanctuary of Filth is the sixth map of episode Blood Stained Earth of No End In Sight. It was designed by Emil Brundage (NaturalTvventy).

Sanctuary of Filth was featured in Doomworld's Top 100 Most Memorable Maps, placing 60th. The Unity offical add-on version replaces this map through a DMAPINFO entry with E4M0: RGC Alpha, due to an error with tall sectors which could not be fixed without gutting the map. On PC, this level includes a secret exit to RGC Alpha for source ports that support the MAPINFO lump and custom linedef types.

Essentials
Be ready to move as soon as the level starts, as there are multiple barons of Hell in front of you. Go up the steps then head north-east to find a narrow marble walkway next to a nukage pool, which you can follow north past a cyberdemon and more barons to a small door. Go through the door and follow the gray walkway behind it north until you reach some stimpacks and a box of bullets, then turn right to see some marble stepping stones guarded by imps. Head east across the steps and go past the cages in front of you, which will lower to reveal spiderdemons, then continue east across some more marble steps to another gray walkway with an armor. Follow this walkway south to another door, open it then head south past another cyberdemon (or two on Hurt Me Plenty (HMP) skill level) or higher) until you reach an outdoor area with three barons.

Press the vine-covered switch in the north-east corner to lower a lift in the opposite corner with imps, then ride this up to a small room with a zombieman and a spectre. Press another switch on the north wall to lower a second lift, get on it and wait until it returns to its original position, then follow the passage north until you reach a gray ledge which you can follow round an icky wall to find a doorway leading to a tan passage. Follow the passage and go through the door that opens ahead of you, then step on the lift behind it which will carry you up to a red key door and a white teleporter. Step into the teleporter to reach a similar room on the west side of the level, then go through the south-east door to find a blue-floored room that contains a yellow skull key and a light amplification visor.

Retrace your steps to the room where you confronted the zombieman and spectre and lower the north lift again, but this time enter the passage at the bottom of the lift to find a baron and two spectres at the bottom of a staircase. Climb to the top of the staircase to find a plasma gun and chaingun next to a yellow key door, open the door then step across a pillar with a health bonus to land on a ledge with three rocket launchers guarded by zombiemen. Step off the ledge and a bridge will rise across the nearby nukage pit - cross it and open the door at the other end to enter a room with a BFG9000 surrounded by nukage (which contains a cyberdemon on Ultra-Violence (UV) and Nightmare (NM) skill levels). Flip the switch at the north end of the room to reach the weapon and raise all the nukage pits in the room, then enter either passage in the north-east and north-west corners and follow them round to a button which will open the wall ahead of you. Step past this wall and flip another switch behind it, which will change the heights of the three spiderdemon cages to the north.

Kill all three spiderdemons and run north along their platforms until you reach two energy cell packs, then go down the steps to find several zombiemen and a cyberdemon (or two on UV and NM) guarding a blue keycard. With the blue key, return to the ledge where you found the rocket launchers then head south-east down a passage leading to a skull switch next to a skin wall. Press the switch to open the wall and kill the spectres and baron waiting behind it, then continue heading south through some nukage until you reach a wooden door. Open the door and take a radiation shielding suit and a plasma gun, then walk south until you drop off the ledge to a white platform far below. Press the blue skull switch on this platform then run south into a nukage pool and climb the stairs you can see rising in front of you.

Take the chaingun at the top of the stairs then head south to find a gray doorway being guarded by several barons and other monsters. Go through the doorway to a grassy area and continue heading south to a rocky platform over a deep nukage pit - there are some shotgun guys on the platform guarding a plasma gun and a switch, and on HMP or higher you will have to contend with cyberdemons firing rockets at you from the other side of the pit. Flip the switch and a bridge with several barons will start to rise over the pit; once it has risen, cross the bridge and go through the exit door on the other side. Flip the switch here to move on to E4M7: Vacuum Consortium.

Secret exit
After killing all of the cyberdemons the walls on either side of the normal exit switch will lower, allowing you to reach Secret #15. If you are using a source port that supports adding custom linedef types through a map translator then the south wall of this secret will be open, allowing you to climb the stairs behind them to a secret exit to E4M0: RGC Alpha.

Other points of interest
As well as the yellow skull key mentioned in the walkthrough above, there are two other yellow keys that can be reached elsewhere in the level.
 * Step into the teleporter in Secret #13 to reach a grassy area on the south side of the level. A yellow key can be found by the east wall.
 * South of the blue-floored room is a nukage pool with an invulnerability. A yellow key can be found on a marble step in this room.

In the room containing Secret #9, look at the south-west corner of the room to see an arrow pointing at a wall. Open this wall and follow the narrow ledge behind it to a button that will lower a very tall pillar in front of you with a teleporter pad. Run south off the ledge to land on the teleporter, which will send you to an enclosed area - go down the stairs here and walk round a marble wall to find the red skull key.

As soon as the level starts, go up the steps in front of you and look right to see a dark alcove containing a chaingun, a rocket launcher and three boxes of rockets.

There are two tall pillars in the nukage pools on the north-east and north-west sides of the level that have switches next to them; pull each switch and the pillar next to it will slowly lower. The west pillar holds a plasma gun and a radiation suit, while the east pillar holds an invulnerability.

Secrets

 * 1) After stepping off the ledge with the rocket launchers, the bridge over the nukage raises up. Look to the north-west and make a running jump to the alcove you see. If you make it, take the path to get an energy cell pack and a light amplification visor. (sector 131)
 * 2) East of Secret #15 (or from the teleporter mentioned in Secret #12), you can go up a staircase to an ammo depot with a chaingun. The gargoyle switch reveals a secret hall where you can collect health and armor bonuses. (sector 184)
 * 3) From the top of the wall to the south of the spiderdemon pens, jump between the ledge and the southern-most pen to the ledge below, then go to the ledge that has plasma guns on it for the secret. (sector 398)
 * 4) At the north-west end of the nukage halls with crushers, you can open one of two walls to find an area with monsters and ammo. The switch at the north end lowers a pillar containing a supercharge. (sector 487)
 * 5) In the middle of the map is a mostly empty green field which functions as a teleporter maze. The hint to the maze is provided if you look at the maze from the side, but when doing the maze it will be entirely dark. If you manage to go through the teleport maze without teleporting to the start of it, you will access a load of supplies including a plasma gun, BFG9000, an invulnerability and numerous types of ammo. Lots of barons will teleport in as well. (sector 756)
 * 6) On the left side of the sanctuary is a hall with ridges sticking out in the nukage. In this hall is a large metal wall on the left side. Press on this wall to open it and head outside, where you can collect several kinds of ammo and a BFG9000. (sector 807)
 * 7) On the blue-floored area with a yellow key, look past the cage for a satyr switch you can shoot, which opens a wall on the other side. Now go to Secret #4 and use the switch to lower the supercharge pillar, then ride it up, then enter the secret where you can find some weapons and a radiation suit. (sector 1227)
 * 8) A room overlooking the big nukage pit in the middle of the map holds a cyberdemon (on HMP or higher) as well as an invulnerability in the lava pit. Picking up this invulnerability reveals a second invulnerability in an alcove nearby, which counts as the secret. (sector 1255)
 * 9) In the area with the big nukage pit in the middle of the map, hop into the nukage and head along the east side. Just before you reach the corner with the BFG9000, there is an opening you can head to, leading to a secret room with some health and armor bonuses, and you can also collect a invulnerability and a supercharge as well. (sector 1454)
 * 10) In the area with the big nukage pit in the middle of the map, hop into the nukage and head along the west side. Right near a trio of energy cells, there is a lion switch that will lower the pillar it is on. After lowering it, go back to Secret #11 to find the teleporter, which takes you to a silo containing imps, more energy cells and an invulnerability. (sector 1478)
 * 11) In the area with the big nukage pit in the middle of the map, head for the south-west corner of the map to find a teleporter which takes you to a platform leading back to the sanctuary. Instead of entering it, turn south and jump down to the building below. If you do it right, you should land on a building where a partial invisibility, a chainsaw, a box of shotgun shells and a radiation suit are nearby. (sector 1504)
 * 12) South of the teleporter maze and past the red doors is a large lift with a lever switch. Flip it to lower the lift to the area to the south; you will also lower another lift which rises up faster than the one you are currently on. To get this secret, flip the switch once, and then quickly press it again before the lift you are on rises to lower the second lift, then get on the second lift quickly and run through the skinned wall. If you do it right, you will trigger the secret, where you can follow the path of supplies and monsters to a teleporter. This teleporter takes you much closer to Secret #2. (sector 1894)
 * 13) Press on the wall to the right of the starting point that has multiple rectangles on it to find a lift with shotguns. Ride it up for a berserk pack and a teleporter to the southern end of the map. (sector 1984)
 * 14) At the north end of the map, just east of the spider mastermind pens, you can find a passage containing two radiation suits and a megaarmor. The teleporter here takes you to the middle of the map. (sector 2001)
 * 15) By killing all of the cyberdemons on the map, you open up two supply depots next to the level's normal exit. Both of them also lead to the level's secret exit. (sector 2016)

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

The data was last verified in its entirety on December 21, 2021.

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

Technical information
This level uses tag 666 to open four walls at the south end of the level when all of the cyberdemons are killed. These walls block access to Secret #15, as well as the secret exit for source ports that support map translators (a custom linedef type is used to open the final pair of walls blocking the secret exit when the level starts).