E3M6: The Halls of Fear (Heretic)

E3M6: The Halls of Fear is the sixth level in The Dome of D'Sparil episode of Heretic. It is the first level in the game to have a non-boss maulotaur in an unavoidable area.

Official

 * 1) When you have entered the yellow door, you will find yourself in a gloomy hallway with many alcoves. At the western end, there are two switches. You need to press the southern one to open the other main door but the switch will also open the back walls of some of the alcoves. Enter the exposed corridor to the north to get a Silver Shield along with health and ammunition pickups.
 * 2) Similarly, a corridor to the south has been revealed. The place holds a Mystic Urn, a varying amount of Quartz Flasks and some ammunition.
 * 3) The northern switch will raise the starting area so that you can step on its fence and run over a gap to a new zone. A Phoenix Rod and an Enchanted Shield can be found up there. North of the weapon is a passage that will take you back to the start - with a Tome of Power - but a door will open to the west while you proceed. It will reveal a shortcut staircase to secret 2, but when you enter the familiar area again and face east, you will notice that an alcove with a Bag of Holding has become accessible. The place counts as a secret.
 * 4) When you have the bag, return to the bottom of the staircase you came from and go where the Phoenix Rod was. The doorways around the weapon can now be entered to reach a Map Scroll.
 * 5) Another staircase connects to the previous secret area. When you are the bottom step, face north and press the wall to lower it as an elevator. Above, there is a room with many timebombs, a new Bag of Holding and some nitrogolems as well.
 * 6) Go to the end of the aforementioned staircase and press the back wall to open it. Another door will open right behind it revealing a varying amount of ophidians, a Pile of Mace Spheres, a second Mystic Urn and yet a third Bag of Holding.
 * 7) At the blue door, you will find two banners. Go through the false wall between them to find a room with two ophidians that were placed there to fire through a false window. In addition, the area contains a Morph Ovum, an Inferno Orb and Greater Runes.
 * 8) Just when you enter the water of the maulotaur yard behind the green door, two wall pillars in the northern staircase back on the other side of the door will open. They will reveal a chamber with a Shadowsphere.
 * 9) Symmetrically with the previous case, another chamber will open at the southern staircase. It holds a Tome of Power. Note that both secret areas also have disciples and Mace Spheres in them.
 * 10) When you are about to take the blue key, the water level of the maulotaur yard will go down and a sheltered area will be exposed on the bottom. There are the Wings of Wrath, ammunition for the Hellstaff and a varying amount of iron liches. Use the wings or the teleporter to return up.

Non-official
The water area that surrounds the starting position has a secret door at the northern end of its western side. The door hides a teleporter and a Ring of Invincibility. Use the teleporter to reach the ledge on the eastern side. Collect the Hellstaff and the ammunition.

Firemace
If the Firemace has appeared at the level startup, you will find it at one of six different locations. It is the last chance to obtain the weapon in the episode. In order of appearance, the positions are
 * in the water, near the door of the sole non-official secret.
 * in secret 3.
 * in secret 5.
 * in secret 8.
 * in secret 9.
 * in secret 10.

Bugs

 * In order to pick up all items, the player has to use the no clipping cheat to obtain a Quartz Flask. It is placed in the void 128 map units south of the eastern yellow door.
 * Linedefs 343 and 370 lack their upper textures near the yellow key and secret 6. The flaw causes distorted views on both sides of the downward trap door.
 * Next to the walls, a decorative torch has not been flagged to appear on the two highest difficulty levels. On either of them, the adjacent sector seems to oscillate on its own which suggests that the arrangement was an oversight.