E2M3: Refinery is the third map of The Shores of Hell. Designed by Tom Hall and revised by Sandy Petersen, and the par time is 1:30.
You start off in front of a cage with cacodemons. Get to it, then go either left or right paths to an invisibility. Go southwest into a nukage pool, and then get to the pedestal. Go even more west, then follow the path to the south, then west, until you come to a pool of blood. Fall down, then go up the stairs to the north, then fall down and get the blue key. Open the UAC door, and then backtrack to the cacodemon cage. This time go southeast into a room with the blue door. Go through and follow the route to a room with a lot of columns. Clear out the maze then go northwest, and continue north then follow the route to a room with the exit door to the east. Go through, kill the spectres, and press the switch.
Other points of interest:
To the west of the start is a door. Open it to access a room full of STAR walls with a berserk pack and a chaingun. Unfortunately, the berserk pack does not appear on easy skill levels.
Near the door to the room with the blue key, go north to access a room with barrels and a baron on hard skill levels.
The northeast of the nukage pool has an opening. Go inside to access a rock area with moving floors.
You can see the exit from the start through vines, but it is inaccessible.
- In the room with the blue door is a vine wall. Inside is a nukage pool with a backpack. To access it open the wall to the northwest.
- One of the steps to the threshold to the room with the blue key count as a secret. The secret is not required - the UAC door to the blue key can be open from the marble room!
- The room with the moving pillars has a secret door to the southeast. Open to access a room with a small pentagon nukage pool. Note that the door can only be open from the pillar room.
- The southeast of that room is another secret door. The door can only be open from the room itself.
- The nukage pool near the exit has a passage to the east. Follow it to a secret area with a soul sphere.
- The southeast of that nukage has an alcove with a radiation suit.