MAP04: The Focus (Doom II)

MAP04: The Focus is the fourth map of Doom II. It was designed by American McGee and uses the music track "Between Levels".

Walkthrough
Go through the door in front of you at the start of the level. In the next hall, go straight up the short staircase and flip the switch in the room at the top. This lowers the blue keycard later in the level (A). Return to the hallway and head to the other end (B) and through the door. To the left is a locked blue door, so continue right along the path until you reach the blue keycard. After you've retrieved it, head back the way you came. On your way back, you will be ambushed by a group of imps from a newly opened closet (C). Head back to the blue door by continuing to follow the path or by going through secret #2.

On the other side of the blue door, flip the light switch next to the door if you like. Make your way to the end of the hall and through the next door. In the next room, stand on the small box in the corner near the door to cause a crate in the middle of the room to lower. Ride it back up to get the red keycard (D). Go through secret #3 for a shortcut back to the red door near the beginning of the level.

Pass through the two red doors (E) and walk along the walkway to get the yellow keycard (F). Be prepared, as you will be ambushed by several chaingunners when you pick it up. Drop down to the left side of the walkway you are on and follow the tunnel to a teleporter (G), and go through. When you reach the other side, flip the switch on the wall to raise the exit walkway (H). Go through the teleporter to your left to be teleported back onto the raised walkway. Go through the now-accessible yellow door to the exit switch.

Secrets

 * 1) At the far end of the first "L"-shaped hallway is a wall with blue triangles on it (I). Open this wall to access the areas behind the shutter windows.
 * 2) Just before the platform where the blue keycard is found is an area with a seemingly inescapable pool of brown sludge. In fact, there is a misaligned texture on the northern wall of the pit that can be opened to get out (J). Inside is a super shotgun and ammo.
 * 3) From the crate the red keycard is resting on, drop down to the left. There is a secret teleport that takes you to an area earlier in the level (K).

Bugs
The back side of linedef 456 is missing an upper texture. This is not easily noticable in vanilla doom because it is obscured by crates, however in source ports that allow jumping or flying, it is clearly visible.

There is a demon in the toxic slime pit that does not appear on any difficulty levels.

Routes and tricks
With some skills, it is possible to reach the exit without raising the walkway that leads to the exit chamber. To do so, you can strafe jump from the left platform to the center platform. This may take a few tries to accomplish.

Records
The Compet-N records for the map are: