Turn to face the huge cybernetic face of the boss on the wall over the platform across the series of steps. Stand on the pillar and select the rocket launcher. The square pillar will lower to the floor as an elevator. When the pillar-like platform in the slime has stopped rising, press on its side. A small platform in the slime pool at the bottom of the steps will rise up.īefore heading up, if you are playing the level using the Ultra-Violence or Nightmare! difficulty, kill the revenant - it may disrupt your rocket attacks. Get to the top step and use the demonic switch found there. Be ready to defeat or bypass the first monsters created by the boss and be careful with the incoming cubes as they may telefrag you, independent of whether or not you are invincible by means of the God mode or invulnerable by means of the invulnerability artifact.
Each step in the simple construction is an elevator which can be activated by pressing on the demonic face on its side. It can spawn any monster in the game, with the exceptions of the bosses (the cyberdemon and the spiderdemon) and the different kinds of former humans, who are not demonic in nature. The Icon of Sin will make its unholy introductory speech and then immediately begin spawning monsters endlessly.
You will arrive at the lowest one on a series of large step-like platforms. Pick up the weapons and powerups and go through the teleporter. Sector numbers in boldface are secrets which count toward the end-of-level tally. Letters in italics refer to marked spots on the map.