This level occupies the map slot MAP22. For other maps which occupy this slot, see Category:MAP22.
After lowering the lift at the map start, take the western route with the bend to the north. Behind the door, push the recess in the wall to your left to lower the wall in front of you. Grab the backpack in the niche (sector 79).
Ascend the stairs from the hallway where secret #1 is found, walk through the door and drop down into the western slime pit. Enter the section in the southwest with many steel beams and go to the south. Before you pass the final pair of steel beams, lower the darker wall to your left and enter the room (sector 210) to find a bullet box, a shell box, some (six on easy, twelve on medium and hard skill levels) rockets, a energy cell and two radiation suits.
From secret#2, return to the slime floor and follow the winding slime path to the south. After dropping down into the hole, walk under the northernmost octagonal slime fall to find a platform (sector 222) with a berserk pack on it.
After removing the blue bars, follow the slime path to the east and enter the stairs to the north. Step on the first, second or third stair and look to the southwest. Shoot at the back wall with a pentagram and a demon face on it in the sergeants' room to reveal a soul sphere upstairs in the west (sector 227).