E5M3: Quay (Heretic)

E5M3: Quay is the third level in The Stagnant Demesne episode of Heretic Shadow of the Serpent Riders. It contains an entrance to the secret level E5M9: Skein of D'Sparil (Heretic).

Essentials
From the start, head up and find both an Ethereal Crossbow and a Tome of Power. Some fire gargoyles are waiting and an iron lich may try to snipe you from afar. Once you're geared up, drop down into the water and step onto the platform to the immediate northwest to lower a wall revealing more ammo and a Silver Shield. From the spot where you got the shield, head upstairs and find a yellow key, along with a passage that's opened onto the platform you dropped down from. When you drop into the large water area again, be prepared as there's now an open ambush containing a pair of iron liches. The chamber they emerge from contains some supplies that you may want including a Ring of Invulnerability. Now enter the large gray building via the open stairway.

Inside, you'll probably want to explore the large bridge room for supplies, but once you're done, take the higher of the two yellow doors. The area beyond is guarded by ophidians and overlooks the platform with the green key. Hit the switch you find nearby, which will raise stairs to the key and also release iron liches. Dash down onto the stairs, or if you prefer to play it a little safer with the lava, backtrack to the bridge room and use the other yellow door before you collect the green key using the stairs you just raised. Before you go, don't miss the Dragon Claw tucked on the lowest step, then either dash back to the upper level from the top of the stairs or teleport out using the side teleports in the lava.

Now that you have the green key, open the lower green door and draw aggression from the monsters inside, including a maulotaur. The maulotaur will be easiest to deal with if you can coax it into pursuing you into the bridge room, where you can then either fight it with space to dodge or simply avoid it. Now take the higher of the green doors and you'll come to a large dark room with barrels along the edges. The platform on the far side marked with banners is a lift activated by using the middle banner. If you're wand starting, this would be a good time to collect the secret Hellstaff from a nearby area. Now go up the lift to the corridor that loops back to the other green door, and find two banners matching the ones used to activate the lift. These are hidden doors, the one nearer the low green door having a switch to lower the blue key, the other having the key itself. Taking the blue key lowers an ambush with even more ophidians.

Returning to the bridge room and heading upstairs past the blue door leads you to a confrontation with the iron liches who were sniping you near the start. You come to their overlook where you'll find another switch which you should pull. You can also drop down to the ledge containing the Phoenix Rod and other desirable items; the wall with the banner activates a lift back up when used. Go back to the green key area and into the better-lit room of tan brick adjoining the Tome of Power room. The exit door has been opened and you can go inside, head down the corridor to pull a switch which lowers a small ambush in the room behind you, then head back and step onto the exit teleporter if you want to take the standard exit and go to Courtyard.

Official

 * 1) Backtrack to the very start of the level any time after you've climbed to the top of the stairs leading out of that chamber.  Walls have lowered revealing some items including a Bag of Holding as well as some ophidians guarding the stash. (sector 22)
 * 2) The iron lich monster closet that opens when collecting the yellow key is considered a secret. (sector 48)
 * 3) Do the steps necessary to complete the level, but instead of taking the standard exit, go back to the bridge room and find a new chamber open in the water near the blue door.  Take the teleport inside and find yourself in the ophidian tower, where you can pull a switch that opens the wooden bars.  In the chamber past the bars, the southeast wall is fake, with gargoyles coming out from behind it.  Beyond the fake wall is an alternate exit which will take you to Skein of D'Sparil. (sector 84)
 * 4) In the large room with barrels along the sides, past the green door, drop off of the lift onto the barrels themselves and use them as a walkway.  Following the north side path leads you to an Enchanted Shield beyond which is a secret door allowing you to escape the lowered chamber you drop off into. (sector 87)

Non-Official

 * There's a Mystic Urn that can be collected much like the Enchanted Shield, just following the barrels on the other side of the room. It is not marked as secret.
 * On the approach to the standard exit, the walls marked with a spinal column motif can be lowered, leading to a Hellstaff.
 * Past the blue door at the top of the stairs, the wall with the banner is a secret door. Beyond can be found Gauntlets of the Necromancer.

Firemace
In case the Firemace has appeared at the level startup, you will find it from one of six different positions. In order of appearance, they are located:
 * Early water area, tucked to the south of the platform that will be reached later through the blue door.
 * Lava surrounding the green key, west side.
 * Lava surrounding the green key, east side.
 * Near the switch which grants access to the blue key.
 * Near the standard exit.
 * Just before the teleporter to the ophidian tower.

Player spawns
This level contains four spawn points:
 * 1) facing west. (thing 199)
 * 2) facing south. (thing 200)
 * 3) facing west. (thing 201)
 * 4) facing west. (thing 202)

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