One of my first maps for Hell Revealed and still I like it a lot. This is a large underground base, and the first real challenge in Hell Revealed. If you can't stand Ultra-Violence - this is the time to switch to a lower skill level. The last level in the first episode of Hell Revealed has no mercy (3 cyberdemons, 2 spiderdemons, 16 archviles and a lot more).
Down some stairs west of the first room is an room with some circular pools of water. Stepping in one of them will cause a door to open in the northwest corner of the previous room (which you can hear). Inside is a plasma rifle.
Near the red keycard is a stairway leading back up to the first room. Next to this stairway is an "alley" with a green torch at the end; open the wall directly north of the torch to get a soul sphere.
A ways into the level, there is a big wooden room with four huge octagonal pillars in it. There is a lift on the south side of the southwestern pillar; ride it to the top. From where you stand, run across the gap onto the next platform, and continue running straight forward through the wall. You will fall down into a secret area with some goodies.
Behind the red door is a room with a raised partition dividing the area in half, with lowering platforms on either side. Ride one of the lifts up, then straferun onto the partition (it's hard to stop without falling off of it, so it may take a few tries to perform successfully). Once on top of the partition, you'll see that it continues into recesses on opposing walls. open the back wall of the eastern recess to get some rocket ammo.