MAP12: Darkdome (Eternal Doom)

MAP12: Dark Dome is the twelfth level of Eternal Doom and was designed by Sverre Andre "Cranium" Kvernmo.

Walkthrough
You start outside the outer building of the castle. To raise the drawbridge, face it and then back up into the alcove of the outside building. At first this switch to raise the bridge will not be visible. You must first explore the nearby areas to the left and the right to find a switch which enables the bridge switch. There is a switch on the inside of the left pillar which raises the bridge. Note that there is a yellow key switch inside the outer buildingY1

On the right, the moat leads to a secret containing the rocket launcher (see secrets).

Once you've raised the drawbridge, go across the bridge and head to the right of the main door. Enter the small hallway to the right of the main door and hit a switch to raise some stairs. At the top of the stairs there is an 'X' switch which will open the main door. At this point, you might as well look out the window and kill the chaingunner in the main hall. The small hallway to the left of the main door goes down to some railing areas with Imps in it. Kill the imps and a Hell Knight in there if you want, and collect a green armor, or you can do it once you get to the part where you need the yellow key, as it has yellow key switchY2.

Go back to the front, and watch out for a chaingunner right behind the main door. Enter the castle and watch out for two shotgun guys right inside the main door to the left and right. If you enter their alcoves (where they spawned) this will spawn some flaming skulls from the torches, as will picking up the items to the left and right of the entrance to the main hall. Open the door to the main hall (see secrets). When you enter, watch out for more flaming skulls spawning from the fireplaces to the left and right of the door. Proceed up the stairs and watch out for the Cyberdemon who protects the castle.

Kill the imps and such in the stained glass windows on the left and right sides of the hall, avoiding the Cyberdemon's rockets. At the rear right there is a Revenant in an upper cross stained glass window (red and yellow instead of blue). At the rear left side of the hall is a fireplace containing an Archvile so you should take him out.

Blue key
At the front left side of the hall, enter the first stained glass window and activate an elevator. Ride it up and take out the skull shooting cacodemon guy. You will come to two pillars, run across them and hit the switch to open the wall in the Archivile fireplace room, where the pillars are.

In this room (the Archvile fireplace room) the lowered wall reveals two doors. The one on the left is locked and is guarded by a chaingunner. The one on the right goes into a hallway with a Berserk pack. Go into the hallway and try to get the Berserk pack. You will fall down into a pit with plenty of enemies, including Hell Knights. Take them out. Note the walled off doorway, this is where the blue key is. Exit this area and you will encounter some green stairs with two Revenants on them. Go up the green stairs, past a yellow key switchY3, and they lead back to those two pillars (a wall has opened where the original switch was). Drop down into the fireplace room again and go back into the Berserk pack hallway.

A switch on the right raises the trap door. Hit it, and, as the trap is raising, run across the gap. Do it while it raises otherwise you will fall in the pit again. This leads into a room with some Barons of Hell on some pillars. Kill them and activate the platform at the rear of that room to lower their pillars and collect the items. Off to the side of this room is a small hallway leading to an elevator. Ride it down to outside the castle. When you re-enter the castle, there is a yellow key switchY4 on the left, an elevator in front, and a corridor on the right. The corridor on the right leads back into the Berserk pack pit, but before you get in there, there is a switch on the left. This opens the small doorway which contains the blue key. Get the blue key.

If you want, go back to the room you were just in and ride up the elevator in the middle. Run across the gap into the window once you reach the top (strafe-run if necessary). There's more Hell Knights. Follow the hall and activate a switch on another elevator. At the bottom is a yellow key switchY5. Go back up on the elevator and the other side of the room leads to the (now unlocked) door back into the Archvile fireplace room.

Go back to the main hall. The blue key door is at the right rear of the main hall, where the Revenant in the red/yellow upper stained glass window is.

Red Key
Enter the blue key door. You can pretty much see the red key once you get in. Go to the back of this room and the red key will lower--but also the Cyberdemon will come after you!!1 Kill the Cyberdemon and collect the red key. At the back of the red key room is an elevator with a yellow key switchY6.Go back to the main hall. The red key door is at the left rear of the main hall, where the Archvile fireplace is.

Yellow Key
Enter the red key door. There's some Mancubi to kill here as you go down the hall. Once you get in the room, there is the yellow key door and a regular door. It is the room you could see from where you got the red key. Go to the other side of this room and into the door. Follow the greenish stairs and hallway up, fighting another Archvile, and enter a room with a blue 'x' shape on the floor. Kill the Spectre Demons. Further on, there is another 'x' shape on the floor made out of fire in the adjoining room. An Archvile and a Revenant will come out of the fire floor so look out. A small hallway on one side is an elevator leading down to a yellow key switchY7. You might as well go down and kill the enemies there. Go back up and go through the door from the fire 'x' room. There's some shotgun guys to the left and right as you come through the door. Ahead is the room with the yellow key in it. There is a big square wall in the middle of this room. On the left there is a switch. Hit the switch and a staircase spirals up around the room. There are plenty of Cacodemons here. Go all the way up the stairs and hit the switch. I think this activates the yellow key switches, and makes them flash.

Don't jump through the gap to get the yellow key just yet, because you will land in the lava and then burn to death because you can't escape. Now that you have activated the yellow key switches you need to go back and press them all, making it so you can activate all the switches surrounding the yellow key, which will raise the lava so you can get it. All the yellow key switches, Y1-Y8 are flashing yellow and you can press them. Go back down the stairs and enter the left side (from this pov) small hallway. There is a yellow key switchY8 here. Watch out because new badguys including Hell Knights appear around the switches. If you want, you can strafe run across the gap to the other side to pick up some health and energy packs (the other door is only opened from this side).

Go back and press all the yellow key switches. They are labelled in this walkthrough as Y1 through Y8. Once you have activated them all, go back to the yellow key room. You can now press the skull switches (which correspond to which yellow key switch you have pressed so far). The ones that are flashing are active, meaning you've pressed the corresponding switch in the level. Each of these switches raises the lava a bit and when you have pressed all 8, you can go to the top of the stairs and get the key without burning to death. Note that the Cyberdemon will respawn in the red key door/red key room when you hit Y6. Also, in the Berserk pit, you can now access the mega sphere. Once you have the yellow key, go through the yellow key door (through the red key door, and then on the left)

Open the yellow key door to reveal a teleport. Go through the teleporter and fight the Cyberdemon. He teleports around a lot so your best bet is to wait in a corner and wait until you hear him in the cage right next to you then blast him with your BFG. Once he is dead, hit the red switch. This opens up one of the 'scream' switches. You have to shoot these switches. Once you shoot them all you have access to the Cyberdemon's cages. One of them (in the red key room actually) has a switch in it. Hit the switch to open the exit teleport. Teleport around (or drop down and re-enter the yellow key teleport and go back into the cages) until you get to the cage with the teleport in it. Enter the teleport and finish the level.

Secrets

 * To access the rocket launcher off of the right side moat, click the wall that looks like a door in front of you. This will release a Demon, as well as opening a door to the left containing some shotgun guys. The hall to the left has a switch which opens the door at the end of the water hall with the Demon in it. Time it right so you can get in the hall before the door at the end closes by opening the water door, hitting the switch, reversing back down the stairs (not out the window) and into the hall. This counts towards your secret percentage.
 * When you open the door to the main hall from the main entrance, imps come out of two doors with dead marines on them. These count towards secrets.
 * In the main entrance, run towards the two torches to be transported up to where the blue armor is.
 * In the yellow key room, there is a switch next to the stairs which takes you down to a place where you can get the BFG. Note there is a Hell Knight down there.

The previous level is MAP11: Dawn of the Dead (Eternal Doom)

The next level is MAP13: Drop 'Em (Eternal Doom)