[9-7] E1M6: The Door to Chthon

From the start, jump down into a corridor. At the end, shoot the red Q symbol suspended over lava to open a hidden door to your right. Ride the lift up onto the air ducts, then jump down onto the ceiling of the room below to find a Quad Damage powerup.

Go to the room left of the design suspended over lava and push the button with the Q. Fall into the pit that opens behind you. After the stairs form, walk down. Kill the ogres revealed when bars block your exit, then use the lift that unbars with their death. Jump onto the stairs in the middle of the lava. Trigger the spiked wall, wait for it to pass, and go behind it to find a slipgate leading to a Super Nailgun and a box of nails, plus a landing with a 100 health box.

In the dark room below the start, cross the pit and go to the end of the passage. Turn left to face stairs with a closed door. To the right of the stairs is a column and a large chamber with a big switch. Hit the switch, then go to the side of the column away from the chamber. Shoot the uncovered red symbol. The stairs with the closed door will lower, with a box of rockets at the bottom.

Stay at the bottom of the stairs from step #3 until they rise again. A slipgate will appear down a small flight of stairs. Walk through to a ledge. Across from you is another ledge with a 100 health box.