E2M4: The Ebon Fortress

The Ebon Fortress is the fourth level of The Realm of Black Magic. It's a large and complex castle, composed of numerous corridors, some outdoor areas, Slime-filled moats, and a number of Flooded areas. This level can be very confusing and it is easy to get lost. Most of the fighting takes place in close proximity to the Player.

This level brings back the Rocket Launcher, as well as the Scrag if the player did not enter the level through E2M7. The player must search for the Silver Key in order to proceed, and can collect the Gold Key to get Yellow Armor and Nails.

Quick Level Completion

 * Drop to the floor below and swim in the Water.
 * Follow the corridor to the right until you get to an intersection.
 * Take the left corridor until you reach another intersection.
 * Take the right corridor and press the Button.
 * Return and take the left corridor to an Elevator.
 * At the top follow the corridor down the stairs.
 * Go up the other pair of stairs at the opposite end.
 * Follow the corridor to the end, and take the Elevator to the right.
 * Press the Button and get on the platform that slides out.
 * Stand on the platform until it reaches its first stop.
 * Go up the stairs, cross the bridge, and press the Button.
 * Return to the opposite side of the bridge and jump up the ledge to the right.
 * Collect the Silver Key, and wait for the platform to stop at one of the doorways.
 * Stand on the platform and wait for it to stop at a final platform before dropping. Get off onto the platform.
 * Follow the corridor to the Silver Door.
 * Cross to the opposite side of the room and press the Button.
 * Go up the stairs to the left of the room until you reach a dead end at the top.
 * Turn around and shoot the Button that reveals itself behind a Movable Wall.
 * Turn back around to see the Movable Wall lower to allow you to access an Elevator.
 * Go down the Elevator and get off the platform at the bottom.
 * Look up at the building and shoot the three Buttons to lower the Bars to the exit.

Walkthrough
Collect the Shells to the left and a 25 Health to the right. Go straight down the stairs and collect a 15 Health to the left. Drop down to the bottom of this floor and collect the Nails. If you have any desire, go left to go up an Elevator back to the top of the room, otherwise go right into the Water. Collect the Shells at the bottom and swim into the next room. To the left is a 25 Health and Rockets, as well as an alcove sunken into the building with Nails and a Super Nailgun. Swim to the right and kill the Ogre on the alcove above. Collect the Grenade Launcher on the climbable alcove to the right, and kill the Zombie on the same alcove. In the lower right corner is a small area you can swim down into  (#1) .

Enter the building through the doorway and follow it through a large room. At the end turn left and kill the 2 Zombies. Take the first passageway to the right to kill 3 more Zombies. To the left is an alcove with another Zombie, Yellow Armor, and the Gold Key. Follow the passageway to the left to another alcove with a 25 Health, Rockets, and a Grenade Launcher. To the right are Rockets. Go back to the start of the passageway from the large room and follow the other passageway to the left. Kill the Zombie in the Water, and the Ogre at the start of solid flooring. In the Water to the right are Rockets. At the stairs, collect the Rockets to the left and a 25 Health to the right. In the next room at the bottom of the stairs, collect the 25 Health to the left and Shells to the right. Collect the Rocket Launcher in the middle of the room and kill the Fiend that comes out from the next room. Collect the Green Armor at the intersection of the next room, and follow the hallway to the right. Collect a 15 Health at the end and turn right. Kill the Death Knight and push the Button at the end of the passageway. Return to the intersection and take the hallway to the left. Collect the 15 Health at the end and turn left. Kill the Fiend and follow the hallway down the stairs. Collect a 25 Health, Nails, and Rockets at the bottom, then take a left at the alcove to the far right of the room to go up an Elevator. At the top collect a 25 Health and turn right to the platform overlooking the area with  (#1) .

Continue to the next room and go down the stairs. Turn right and kill the Scrag, as well as the Ogre on the alcove above that may come from the platform overlooking the large Water room at the start, and may have been killed in that room if he came close enough to the edge. Turn around at the bottom of the stairs and go to the right to find a shootable Wall (#2) . To the right is a passageway with Nails and Rockets, as well as the Gold Door to the left. Inside is Yellow Armor and Nails. Straight from the bottom of the stairs is a 25 Health, as well as another staircase. Follow it to the alcove above the room. To the left of the staircase is a shootable Wall (#3) . Collect the Shells further down the hallway on the platform overlooking the large Water room at the start. Turn left while killing the Ogre and collect the two 25 Health, 15 Health, Nails, and Biosuit. Continue on the main passageway to an Elevator to the right at the end. Press a Button to the left to cause a series of Moving Platforms to start sliding across the Slime in a conveyor belt style. Turn left and kill the Ogre at the first location the Moving Platform stops for a moment at. Climb the stairs, and to the right is the second place the Moving Platform stops at. Instead turn left and collect the Shells and 15 Health by the stairs. Drop off the platform to the right and swim through the passageway of Slime to get to an alcove  (#4) . Climb the second flight of stairs and cross the platform overlooking the Slime with the Moving Platforms. Collect the Nails at the end, and turn right to collect Shells and press a Button. Bars lower to the left, or now the right, of the second staircase; revealing a Fiend, two 25 Health, Green Armor, and the Silver Key.

Return to the Moving Platform by use of the first or second stop location. Collect the Quad Damage located in the Slime between the two locations. The Moving Platform shall continue to a third location, where you get off, before dropping into the Slime to restart the conveyor belt. Collect a 25 Health and 15 Health to the right and drop to the lower floor. An Elevator allows for returning if the player desires. Follow the passageway to the right to collect a 25 Health at the end. Turn left and kill the 2 Scrags, as well as another Scrag that spawns behind you. To the right is the Silver Door, but first follow the passageway and collect a 25 Health. There is a doorway here which leads to the Elevator that has opened up on the left passageway of the room with the Rocket Launcher. To the left of this area is an area overlooking that room. After following the next passageway there is a Button that can be shot to the right of the doorway from the Water. The passageway mentioned is to the left and leads to an area overlooking the stairs on the left passageway from the Rocket Launcher room, or if the Button was shot, a passageway leading to a Zombie, Quad Damage, Nails, and 100 Health. Enter the Silver Door room and collect the Shells to the left. To the right of the stairs is an alcove with a 15 Health, Death Knight, and Button. Climb the stairs and kill the Ogre to the right further up the stairs. At the first turn are Rockets and Shells. Follow the staircase to the top and kill the Shambler. There is a Movable Wall at the end, so turn around and shoot the Button on the wall that appears behind a Wall that moves when you move down the top platform to lower it. Kill the Ogre behind and press the Button to lower the Elevator. At the bottom, to the left is Shells and to the right is a 25 Health. Kill the Fiend on the grassy area below, and collect a 25 Health and Shells to the right. The Arch is blocked, so turn around and look up on the building you exited from to shoot three Buttons, removing the Bars from the Arch.

Differences from Easy to Normal

 * Death Knight in starting room just before Water
 * 2nd and 3rd Ogre on platform overlooking  (#1) 
 * Grenade Launcher on alcove by  (#1)  has been replaced with Nailgun
 * Zombie in passageway just before large Water room
 * Scrag in large Water room
 * 7th, 8th, and 9th Zombie in Gold Key room
 * 2nd Zombie and 2nd Ogre in final Water room
 * 2nd Fiend when Rocket Launcher taken
 * 2nd Death Knight by Button on right passageway from Rocket Launcher room
 * Death Knight by stairs on left passageway from Rocket Launcher room
 * Fiend at bottom of stairs on left passageway from Rocket Launcher room
 * 2nd Scrag in Gold Door room
 * Ogre by  (#2)  in Gold Door room
 * Ogre on platform overlooking Gold Door room
 * Fiend by Gold Door
 * Death Knight by exit staircase of Gold Door room
 * 2nd Ogre on left passageway overlooking large Water room by Biosuit
 * Scrag at start of Moving Platform
 * Scrag by first stop of Moving Platform
 * Ogre at top of second staircase in Silver Key room
 * Ogre on platform overlooking Moving Platforms
 * No two 25 Health by Silver Key
 * 3rd Scrag spawns in hallway overlooking Rocket Launcher room
 * Ogre by area just past Silver Door accessed by shooting the Button on the wall overlooking Rocket Launcher room
 * 2nd Death Knight and Ogre on bottom floor of large staircase room
 * 2 Ogres and 2nd Fiend in final room
 * Glitch prevents 4 Scrags from spawning

Differences from Normal to Hard/Nightmare

 * No 25 Health to the right from start
 * 2nd Scrag in large Water room
 * 3rd Zombie, 3rd Ogre, and Death Knight in final Water room
 * 2nd Fiend by stairs on left passageway from Rocket Launcher room
 * 3rd Scrag in Gold Door room
 * 2nd Fiend by Gold Door
 * 2nd and 3rd Ogre on main platform overlooking large Water room
 * Scrag by first turn of Moving Platform
 * Scrag by last turn of Moving Platform before first stop
 * 3rd and 4th Ogre on staircase of Silver Key room
 * Shambler instead of Fiend by Silver Key
 * Fiend on bottom floor of large staircase room
 * 3rd and 4th Fiend in final room

Glitches

 * On Normal and higher Difficulties, 4 Scrags do not spawn because of a missing trigger. This has been fixed in the enhanced version.
 * The player may Grenade Jump or Rocket Jump to the Silver Door room from the Rocket Launcher room, but must backtrack somewhat to reach the Silver Key.
 * The player may Grenade Jump or Rocket Jump to the platform with the Silver Key from the lower floor without lowering the Bars.
 * The player may Grenade Jump or Rocket Jump above the Bars blocking the Arch to avoid the Enemies below and to get a better shot at the 3 Shootable Buttons.

Differences

 * 25 Health to the right from start returns
 * A passageway in large Water room leads to a climbable area on the right leading to the exit stairs of the Gold Door room
 * No Button on right passageway from Rocket Launcher room, instead 2 Cells.
 *  (#3)  contains a 100 Health instead of Pentagram of Protection
 * Long platform hallway instead of Moving Platforms
 * Two 25 Health by area where Silver Key used to be return
 * At top of large staircase is 2 Cells and the Thunderbolt

Spawn Locations

 * Rocket Launcher room
 * Thunderbolt room
 * Area where Silver Key used to be
 * Gold Key room
 * By Elevator leading to prior Moving Platform
 * Balcony overlooking Nailgun room
 * Small room just after starting Elevator
 * Room just after prior Moving Platform third stop Elevator

Trivia

 * Sections of this level were apparently made around August 3, 1995; certain rooms are highly recognizable based on screenshots released on said date.