Doom/E4M7: And Hell Followed



At the start, take out the solders in front of you, and work your way to the south-west of the map. The doors on the south will instantly open on approach and have two monsters there. You may want to aim on the right hand side of the door to get the shotgun guy.

The key is on the window overlooking the outside. Grab it, the partial invisibility and the rocket launcher before heading to the door in front of the start.

You may want to collect better weaponry before you proceed, or at least restore health and get armor. There is more information located under weapons and secrets concerning this information, but the plasma gun may be the best option for dealing with two barons of hell.

Jump into the slime chasm in the middle, grab one of the four radiation suits, and run to the left. Open the door and go up the lift. There is a Baron of Hell here. Flip the switch on the blue wall and wait for it to lower to reveal a switch and another Baron of Hell. Flip this switch as well.

This raises platforms to the center of this area. Head onto the circular platform and exit the level by flipping the switch.

Weapons

 * A shotgun is right in front of you.
 * A chainsaw is in the northwest section of the corridors.
 * A berserk pack and Chaingun are in the south-east chamber.
 * A rocket launcher is located in the south-west chamber. You must walk towards the staircase ontaining green armor from the north in order to reach it safely.
 * A plasma gun is in the northern section, on the eastern balcony (accessible from the slime chasm)
 * A second rocket launcher is in the western balcony.
 * A BFG and rocket launcher are located in the yellow key area, described in the secrets. These weapons only appear in this location on Ultra violence or Nightmare.

Secrets
A quasi-secret involves a region between the two southern chambers. Use the large doors between them to reveal a computer map.

To reach the secrets, you need the yellow and blue keys. For the blue key, head to the east corridor and one of the doors on the right. The upper one has an ambush from behind, while the lower one gives access to a mega armor.

From these rooms, you should be able to access a dark room. Flip a switch to reveal a supercharge; this can safely be taken from the side, but to get the blue key, you need to approach it from the front. Kill the imps and take the blue key.

To get the yellow key, head to the south-west chamber (although you can take care of the monsters earlier by going to the southeast chamber and opening the east door). Open the blue key secret door on the left. Jump in the teleporter and get the yellow key in front of you.

The secrets are now accessible. In the southern chambers, open the doors to the south. Firing in this section will cause either a Baron of Hell or Cyberdemon to teleport in. However, a bug with the map only allows you to obtain 50% of all secrets.
 * 1) At the southern section of the room, open the door behind the BFG (or boxes of rockets).  On Ultra Violence, you can get a rocket launcher, super charge, and invulnerability; otherwise, there are two medikits.  When you kill the imp, a cyberdemon or Baron of Hell will teleport.
 * 2) On the northern section of this room, flip the switch.  In the eastern exit corridor, a door will open revealing medikits, mega armor and rockets.  Additional rockets are available on Ultra Violence only.

There are two inaccessible secrets on the map, which can only be obtained by cheating:
 * 1) In the secret behind the BFG, open the left door for a second invulnerability orb.  To claim the secret, you needed to go directly under the door; however you are blocked by the platform containing the invulnerability, leaving a space too narrow to claim the secret.
 * 2) This second invulnerability is a secret itself.  To claim it, you need to walk on the platform it is stored on, which is impossible.