SECRETS

E3M1:

1. At map-start, turn right and press the lion's head to open a wall to your South. Press the skin switch to raise the floor, then proceed South to enter the secret area. Gives you the chainsaw.
2. When you enter the main area (to your North-East), look for a satyr's head on the right wall. Press it and run around the curved corridor to enter the area with the rocket launcher.

E3M2:

1. After you pick up the chaingun in the middle of the map, turn South and look for a pillar with a different texture. Press it to lower the pillar. Gives you a berserk pack.

E3M3:

1. Before you enter the lava area with the rocket launcher, look for a wall with a solid TEKWALL texture. Press it to open the wall. Gives you a radiation suit.
2. After you go through the big blue-key door and cross the lava area, look for the Satyr face on the left and the Lion face on the right. Press the Satyr face to open the wall of skulls in the room around the corner. Take the stairs up to score a berserk pack.

E3M4:

1. The floor of the giant crusher is the secret area. You must jump in from the South side of the pit (after timing it properly), which will then raise the floor and allow you to slide out from under the crusher before being pulverized. There's a small arrow as a clue regarding where to jump in. If you jump in from anywhere else the floor will not rise and you'll be crushed.
2. In the room with the skull-switch pillars (where you find the red skull key) press the switches on the North side of each of the pillars. It will allow you access to a secret room with a BFG.

E3M5:

1. From the start, take the Western-most door and immediately turn right. You'll see a slightly recessed area in the wall. Shoot the wall to open it. Box of shotgun shells in the secret area.
2. From the start, take the Eastern-most door in the damaging blood and immediately turn left. You'll see a slightly recessed area in the wall. Press the wall to open it; radiation suit in the secret area, which will allow you to pick up the nearby SoulSphere without taking damage.
3. In the area with the rocket-launcher, there is a wall with a splayed Baron of Hell. Press it to open a door to a secret area with a blue armor.
4. In the area with the yellow key, when you pick up the yellow key a lift quickly lowers nearby. Run to the lift before it rises, and press the slightly recessed area in the wall. The wall will open to let you use a teleporter to the secret area with the computer area map.
5. In the damaging blood area to the North-West quadrant of the map, run around the circular passageway and look for the two blue symbols at the end. Press the wall between the two symbols to open the wall; there's a radiation suit in the secret area.
6. After you find the secret in 5, above, continue around until you enter the second circular passageway. Shoot into the blue symbol to open the bar that blocks the far end of the passageway. Follow around to drop into the secret area with the BFG.

E3M6:

1. When you enter the green stone building to the West, climb the steps and look for the gargoyle face that is misaligned. Press it to lower a wall to your left, go through to the teleporter, and pick up the plasma rifle in the secret area.
2. When you enter the vine-covered building on the Eastern end of the island, you'll see one teleporter that is inaccessible and one that is. Use the latter to teleport inside the wooden building to the East. When you have pressed the switch that lowers the teleporter to get you out, you'll teleport to a ledge outside the vine-covered building. Go back inside and go to the other teleporter, which is now accessible. Teleport to the secret area inside the central building with the invulnerability on the pillar.
3. When you have picked up the blue key, head for the exit in the rear of the stone building to the North but take the left fork. Press the switch to your right (to lower the pillar blocking the secret area) and walk through the teleporter. This will teleport you to the watery area at the South. Walk right around the ledge to the spot above the blue pit. Face the wall and simultaneously fire a rocket against the wall while running backwards. [Use the invulnerability in Secret 2 to avoid splash damage from the rocket.] You will drop into the blue pit, where there is a switch to take you to the secret level.

E2M7:

1. At the other end of the blood maze with the red skull key, is a pillar with a blue skull key. To lower the pillar, enter the area that leads to the blood maze, but don't run across the blood moat to the steps just yet. Instead, turn right and you'll see a window overlooking the pillar with the blue skull. Nearby is a switch that lowers the pillar. Cross the blood moat, drop into the blood maze, and head Southeast towards the blue skull key.
2. When you've picked up the blue skull key, you can go through the blue key door in the area to the South, and take the teleporter to the BFG. [You'll need to press the switch in the passageway near the blue key door to raise a section of the moat to allow you to jump across.]
3. In front of the red key door to the West is a Skin Symbol wall with a flickering light. Shoot the wall to open it; there's a radiation suit, a soulsphere, and a box of rockets in the secret area.

E3M8: No secrets.

E3M9: 

1. When you enter the area to your North-East, look for a satyr's head on the right wall. Press it and run around the curved corridor to enter the area with the chainsaw.