Z1M3: Toxin Refinery (Knee-Deep in ZDoom)

Z1M3: Toxin Refinery is the third level of Knee-Deep in ZDoom, revisiting the original level with some new twists. The secret exit to Z1M9: Military Base is accessible from this level.

Walkthrough

 * Letters in italics refer to marked spots on the map. Sector numbers in boldface are secrets which count towards the end-of-level tally.

Secrets

 * 1) Sector 1894: Somewhere in the corridor on the way to the blue key, the terminal with a red symbol on the screen can be activated. The symbol will go a green, and a backpack will be revealed to your right.
 * 2) Sector 1858: From the same place as secret #1, go up the ladder to the south. You will be taken to a small room, containing useful items, Shadows, and a switch, which the effects of can be seen on the nearby screen.
 * 3) Sector 5965: In the mines, in the last cavern before the labs, the north-west tunnel will lead you to a chaingun and a backpack.
 * 4) Sector 5109: After the aforementioned labs, jump up onto the boxes in the west of the storage area. With some navigation, you will find an alcove containing a berserk pack.
 * 5) Sector 3545
 * 6) Sector 5651
 * 7) Sector 5965
 * 8) Sector 6627
 * 9) In the "sunken" area of the mines, while swimming to the north, you'll find a green button switch, press it and then quickly go to the south-east. The grate should be opened and if you can reach it in time, you'll get a black keycard.
 * 10) After activating the switch on Secret #2, go to the outside area full of toxic waste (near the blue key room), then swim deep to the west, you'll find a tunnel there that leads you to a room containing a rocket launcher and some rockets.
 * 11) TBA

Speedrunning
The records for this map at the Doomed Speed Demos Archive are: Last updated on March 17, 2013.

Things
Initially, this level contains the following number of things on each skill level:

Primary mapping

 * Björn Ostmann (Vader)
 * Pawel Zarczynski (NMN)

Secondary mapping

 * Jacob Zuchowski (ellmo)

Tertiary mapping

 * Nick Baker (NiGHTMARE)
 * Fraser Low (TheDarkArchon)
 * Michael Niggel (Risen)