MAP02: Underhalls (Doom II)

MAP02: Underhalls is the second map of Doom II. It was designed by American McGee and uses the music track "The Healer Stalks".

Walkthrough
You start on a platform across a narrow stream overlooking a raised platform with stairs (A), where three Zombiemen are facing away from you. There are two barriers on either side of the stream barring the way to two tunnels leading beyond. Kill the Zombiemen, travel across the stream, and then go up the stairs and open the door. There will be two more Zombiemen to deal with on either side of the door in the small room beyond. In the alcoves on either side of the room are Shotgun Guys guarding two switches. The alcove to the right has bars requiring a red key to open, but the alcove to the left doesn't have any bars. Kill the Shotgun Guy guarding the left switch and then hit it (if you don't feel like fighting the other Shotgun Guy once you get the key, you can kill him through the bars).

The left switch brings down the left barrier in the entrance room, allowing you to access the left tunnel. You will have 3-5 Zombiemen and Shotgun Guys to clear out with your new shotgun, including a Shotgun Guy in the alcove to your right, which has a medikit. To the left further on down the tunnel is a set of stairs leading down to a door. This door leads to a room divided into two parts by a computer terminal. There will be a good number of Zombiemen and Shotgun Guys to deal with in this room, but at the end of the room behind the terminal is a Super Shotgun.

The left tunnel leads to a clearing with a walkway, a building and an opening to the sky (B). There will be a good number of Imps, Zombiemen and Shotgun Guys to deal with both inside and outside the building. Make sure to kill the Shotgun Guys through the smaller window to make things a little easier on you. Follow the walkway to the end where there is a window to the building, then jump through by running. Climb the stairs and then grab the red key. Grabbing the red key will open up two alcoves on either side of the walkway and disgorge a good number of Imps and a Demon to deal with. Kill them and go back down the tunnel. Another secret alcove will have opened on the opposite side of the stairway to the Super Shotgun room, where a medikit and four Shotgun Guys await. Deal with them and continue down the tunnel until you return to the entrance room.

It's a good chance that some of the Shotgun Guys from the building's small window will have teleported into the entrance room via the hidden teleporter in the room they were in, so you will most likely have to deal with one or two of them. Return to the switch room, open the red key bars (C), kill the other Shotgun Guy if you haven't already, and then hit the right switch to lower the barrier to the right tunnel outside.

Just like before, go down the right tunnel until you reach the end and kill any zombie that gets in your way. Both of the doors to the left and right of the tunnel require a blue key to open, and the one to the right has a staircase leading down and two barrels to either side. At the end of the tunnel, you will see a grey platform with a zombie and another barrel (D). Kill the zombie or blow the barrel and kill the zombie.

The next room (E) has two holes in the floor, a number of barrels, and a number of imps and zombies. If you position yourself just right, you can set off a chain reaction that will blow the barrels and kill everything in the room while leaving yourself unscathed. Once everything is dead, take the left-hand hole, which will drop you into a dark room filled with water and barrels. You will have to deal with more Imps, and in a dead-end tunnel to the left, more Imps and a Demon guard the blue key. You can either kill them all normally, or blow the barrels lining the tunnel to make things easier.

There will be an Imp almost right in your face when you open the door to the next room. Kill it, kill the Imp directly to the left, and then blow the barrels lining the tunnel to the blue key door to kill the rest of the monsters in your way. Pick up whatever health items you need, then go through the blue key door and up the stairs. The only door left is the blue door you passed earlier. Go through the door, kill the Shotgun Guys waiting for you, and then hit the exit switch (F).

Secrets

 * 1) At the top of the staircase inside the structure the red keycard is found in, open the west wall just west of the alcove the key was resting in. Behind this wall is a small room containing a few sergeants (G), a combat armor vest, and a teleport shortcut back to the start of the level.
 * 2) Secret exit [ Xbox version only ] : after obtaining the red keycard, drop down, and enter the northeast chamber (H) that has just opened. Walk up to the narrow, stone wall in the northwest of this chamber (I), and press on it to be taken to the Xbox-exclusive secret level, MAP33: Betray. The button that allows you to enter this level is active in the Doom 3 BFG Edition version of the map, however, it will simply take you back to the beginning of MAP02: Underhalls.

Bugs

 * 1) There is a blind Sergeant in the room behind the first door near the start of the map.
 * 2) Behind the bars locked with the red key, sector 39 (the western monitor) is not "closed", because linedef 312 (the southern border of the monitor) originates along the body of linedef 491 (the southwest wall south of the western monitor) rather than its endpoint. This creates a paper-thin wall at the southern end of the monitor.
 * 3) On your way to the blue key, one Sergeant (thing 85) situated near a barrel on a platform south of the main tunnel is immobile due to being partially inside the southern wall.
 * 4) The lower sides of linedefs 327, 328, 338, and 339 are all untextured, producing Hall of Mirrors effects if you stand in any of the small pools you fall into when entering the sewer and face outward.
 * 5) Thing number 69, a barrel (x=464 y=784) is in a linedef because it had the same Y position.

Trivia

 * In the first version of this map, the left alcove of the small room across the river from the start had bars closing it which needed to be opened by the Use key. These were removed from subsequent versions.
 * This level marks the first appearance of the Shotgun Guys in Doom II, and if you didn't get the secret shotgun in the last level, your first shotgun will likely come from the Sergeant you kill to get to the left switch.

Records
The Compet-N records for the map are:

Trivia
The music for this level is inspired by "Samba Briza" by Atheist.

A Shotgun Guy next to an explosive barrel appears to be stuck and can't move, only walk in place.