E5M6: Colonnade (Heretic)

E5M6: Colonnade is the sixth level in The Stagnant Demesne episode of Heretic Shadow of the Serpent Riders.

Essentials
From the start, head down the stairs, collecting the Ethereal Crossbow as you go. Through the large wooden door you find a long corridor with the exit, locked behind a blue door, at the end. There are just a few golems waiting but when you engage them, you'll also alert a large number of gargoyles that will attack from behind, so you may want to get well within the hall before you open fire. At first, only the west side is accessible but you can head up either pair of stairs you prefer. They take you to a long silver room with undead warriors imprisoned in cells along one wall. There are also some hiding behind the green-eyed demon walls at the ends, which are shoot-through but not walk-through. The Dragon Claw can be found between the two cages. Pull the two switches on the west wall of this room, then shoot the red-eyed skull wall in the alcove between them. It opens as a door and a large group of disciples will come out, plus nitrogolems behind them. Inside the chambers beyond are some useful items, including the Ring of Invulnerability, as well as a switch to pull.

Now head back; the central east wall of the silver room is lowering to give you access to the blue room. There's a drop down to reach it and pods all around the room's perimeter making things quite perilous. You might wish to hold off on blowing these up until after the ambush in this room opens, so that you can use the pods to damage or destroy the disciples that come out. You might also want to use the ring you got recently to avoid getting blown up by any pods the monsters hit before you're ready to go. Once the coast is clear, enter the alcove that you entered the room from to lower lifts to either side, taking you into the cages where the undead warriors were. In the south one is a switch and pulling it will let you reach the yellow key. Once you have the key, you can open a shortcut back to the entrance hall by using the walls that have brown grates at the bottom on either corner of the wall adjoining that hall.

When it comes to which yellow door you choose to go through, you may wish to visit the southern one first for the Hellstaff secret. To progress, however, you must pass through the northern yellow door, then open the nearby secret door marked with a red banner. A switch inside will open both a chamber with Gauntlets of the Necromancer and an alcove near the entrance of the building, where you'll find a switch. This switch raises the stairs to the central east area. Head up to a room with many pillars adorned with banners. Several of the pillars have switches on them, and the southernmost lowers a lift at the north end of the room granting access to the green key. Beware, as the stained glass windows are fake walls with disciples and an iron lich behind them.

With the green key, you can head downstairs through either of the yellow doors, then pass through the green door into the water area beneath the green key area's balcony. Find the small corridor into the eastern structure and head up a lift. The first gold trident on the green wall also marks a lift, the next one lowers the wall blocking a switch. As you ascend here, an ambush of many disciples will come out so stay on your toes. Once you pull the switch, you can drop down and climb up the smaller structure to the blue key. Taking the key drops the nearby wall, behind which waits an iron lich. The switch where the iron lich is will lower the border of the balcony above as a lift, letting you get the Phoenix Rod and serving as a shortcut back to the green key room. With the blue key, you can open the exit chamber, which is guarded by merely a lone disciple.

Official

 * 1) Enter the exit chamber to open the secret sector, then backtrack to the silver room, hit the small red-eyed skull wall with your staff, causing it to open.  You can now go straight through and around the bend to get to the lava chamber containing a Mystic Urn. (sector 327)
 * 2) Mirroring the above on the north side.  This one contains a Ring of Invulnerability. (sector 342)

Non-Official

 * 1) The areas behind the red-eyed skull walls that must be accessed for the official secrets do not count as secrets themselves, despite containing hidden corridors and items in their own right.
 * 2) At the bottom of the stairs from the southern yellow door, open the wall marked with a red banner and head down the long winding flight of stairs to find a Hellstaff.
 * 3) In the green key room, the switch that has a spiderweb in front of it drops a lift to a teleporter which takes you behind the starting area of the level, where a generous amount of ammo and some healing items can be found both on the ledges and in the water.  An ambush of undead warriors also resides here.
 * 4) From the green key ledge, the center stained glass fake wall hides an Enchanted Shield while the side ones (opened by the middle of the three switches in the pillar room) lead to a chamber with two teleporters, each leading to a claustrophobic maze with green floor and ceiling.  The switches in these mazes drop the walls, revealing bonus items.  One of these also has a passage leading to the ammo-laden ledge in the green key room, and a Map Scroll.

Firemace
In case the Firemace has appeared at the level startup, you will find it from one of five different positions. In order of appearance, they are located:
 * Corridor behind the south red-eyed skull discussed in secret areas above.
 * Corridor behind the north red-eyed skull discussed in secret areas above.
 * The sequence of opening undead warrior chambers adjacent to the northern green door.
 * One of the claustrophobic green mazes through the teleport behind the stained glass windows in the green key room.
 * The other such maze.

Player spawns
This level contains four spawn points:
 * 1) facing north. (thing 74)
 * 2) facing west. (thing 75)
 * 3) facing east. (thing 76)
 * 4) facing north. (thing 77)

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