This level is a renewed, enpowered and harder version of Hell Revealed's Map22: Resistance is Futile. Due to the high number of Arch-Viles appearing (coming or suddenly teleporting in big groups, most of times in teams of 4 or more, or simply located in the most concentrated amount of monsters, for example the river in the middle of the map) and the meager possibility for the player to find a safe place to shoot monsters without being harmed, this level is one of the hardest maps in Hell Revealed II.
In the yellow key room push the most southern part of the west wall to reveal a Megasphere. (Sector 11)
In the hallway north of the blue door push the east wall to reveal a Megasphere. (Sector 55)
South of the blue door building push the middle part of the south wall to reveal a Megasphere. (Sector 62)
Near the exit, after the wall cut your way back to the main area of the map, push the west wall under either opening north or south from the wall blocking your way back. This way you can access the area where lots of Imps were (or are, if you didn't waste them). You'll find two Super Shotguns and 28 Sets of shotgun shells. (Sector 68)