This level occupies the map slot MAP19. For other maps which occupy this slot, see Category:MAP19.
MAP19: Maltraiter is the nineteenth level of Memento Mori. It was designed by Michael Rapp and uses the music track "Night Bats" by Mark Klem. The level's texturing style changes constantly as it progresses, more so than any other level in the megawad.
"Maltraiter" is a French verb meaning "to mistreat" or "to manhandle."
In the square marble area, right after entering the yellow door, press on the southern face in the entryway. Walk down the hallway to the south, passing a door. Step in the inner corner to your right and the wall will lower to reveal a passageway. Enter it and the next passageway to the west, revealed by the switch you pressed earlier, to find a teleporter. Walk around the teleporter and press on the southern wall with the face on it to reveal a backpack (sector 151).
At the end of the marble area, before the bridge section, press on the eastern wall with the face on it to reveal a secret room (sector 189) containing three (two on easy skill levels) sergeants, on hard skills a revenant as well as a chaingunner or three (easy)/two (medium) imps, a box of shotgun shells, a plasma gun, and three (two on hard) energy cells. Hit the switch near the plasma gun to raise the northeastern stairs leading to an armor bonus. Grabbing it opens the wall across the door leading to this secret, releasing another sergeant.