E2M9: Fortress of Mystery (Doom)

E2M9: Fortress of Mystery is the secret map in The Shores of Hell in Doom, and can be accessed from E2M5. It features some Barons, a horde of Cacodemons and not much else of interest.

Walkthrough
When the level starts you will immediately be attacked by four Barons of Hell surrounding you. Find a safe spot and take them out with your most powerful weapon. Once they've been taken care of, pick up the various weapons and other goodies in each of the "arms" of the first area. Afterwards, go through the door in the eastern "arm". The next area holds eight Cacodemons. Pick up the Soul Sphere in the center of this room if you need it. Once all the enemies have been disposed of, head to the eastern end of this "+"-shaped room. There are two lion-faced reliefs on this wall. Open the wall between them to reveal the level's exit room. Press the skull switch to the left to get the blue key, then open the blue door to get the red key. Open the red door to get the yellow key, and finally open the yellow door to reveal the exit teleporter.

Secrets

 * 1) The exit room counts as a secret.

Records
The Compet-N records for the map are:

Trivia
Prior to entry of the level, the fortress will not appear on the intermission screen. When you enter, the fortress will fade in on the map, and will remain on the map from that point on during Episode 2.