E1M9: Military Base (Doom)

E1M9: Military Base is the secret map of Knee-Deep in the Dead in Doom which can accessed from E1M3.

Walkthrough
Move carefully forward toward the end of the corridor you find yourself in. Kill the imps in the cage in the center of the courtyard and the former humans that enter from the other corridors.

Take the corridor heading due west from the imp cage to find the yellow keycard behind a grate.

You do not need to visit the room to the north in order to complete the level, but there is a rocket launcher there. If you do go for the rocket launcher, a good number of imps and demons will teleport in to that location.

Go back to the central courtyard and down the corridor straight across to the east (detouring around the imp cage). In this room, there is another optional area, ahead to the east and down a lift; it has three imps on tall pillars and a green armor. If you go there, come back up the lift.

Take the secret passage that drops down as you approach the southwest corner of the room. Pick up the chaingun (secret #1). Continue across the nukage to go up the lift in the opposite corner.

Go to the left (south) and then left again (east) and go through the yellow door to get the red keycard. Go back the way you came (west), going around the big box-pillar in the next room, and continue west through the red door.

Go all the way to the west wall and turn left to see a switch behind some barrels. Explode the barrels and click the switch. This opens the big box-pillar in the room you just walked through, releasing demons. Go back to where the big box-pillar was, either the way you came or through the now-open passage to the south behind barrels. Pick up the blue keycard.

Head north up the stairs to the central courtyard, down the corridor straight across (detouring again around the imp cage) and through the blue door. The exit will be visible, but inaccessible, across a nukage canal.

There is an off-texture wall segment to the right (east). Push it to open, and go down the steps (secret #2). You will find a room with items atop pillars. If you want to collect the items, walk toward the far wall. A lift will drop allowing you to ride up to the top of the tallest pillar. Jump carefully from pillar to pillar, counterclockwise in order of decreasing height. For each jump, back up as far as you can without falling off, and run toward the next pillar. Be prepared to stop quickly when you land. If you do happen to fall off, just return to the steps to relower the lift.

Go back to the previous room, jump into the nukage canal, and follow it around either way to a platform with a green switch (and an imp). When you step onto the platform, a door will open behind you releasing more imps. Take care of the imps and click the switch.

Go through the door that the imps came out of. Follow around, up a lift and through another door. Watch out for spectres that have been released. (The spectres come from a hidden compartment in the north wall, which opens at the same time as the imp door in the tunnel.)

The green switch in the tunnel has raised a bridge across the nukage canal. Cross and click the exit switch.

Secrets

 * 1) In the first room east of the central courtyard, the floor in the southwest corner drops down into a nukage pool. Pick up the chaingun in the center of the pool.
 * 2) In the room behind the blue door, there is an off-texture segment on the east wall that is a secret door. Walk through to register the secret.

Demo files

 * [[Media:e1m9secr.lmp|No monsters, 100% secrets walkthrough]] (file info)

Routes and tricks
It is possible to jump over the nukage canal in the exit room by straferunning.

Records
The Compet-N records for the map are: