Eye of the Beholder 2 Walkthrough - The Crimson Outpost
Crimson Tower Access
Using the Stone Dagger on the portal at the end of Level 5 of the Azure Tower takes you to the Priests' Quarters, the crossroads between the towers. Just round the corner from the portal is the door with the crimson lock that you couldn't open earlier. Using the Crimson Key, open this door.
Just inside and to the right, another barrier is before you. Put the Eye of Talon, Hilt of Talon, and Talon's Tongue in the carving. This will cause it to melt away, leaving the newly forged +4 Talon (sword), the most powerful weapon in the game.
As you proceed to the west, there are three routes you can take. The southernmost west passage has two pressure plates, and looks like a dead end. The northernmost west passage has one pressure plate. Between these is a staircase going down to the west.
Going down the central staircase, you face some priests (one of which hurls a fireball). In this area you find a Mage Scroll of True Seeing (Mage Level 6), and also notice the pit in the ceiling.
Crimson Tower Outpost
Go back upstairs, and this time take the northern passage west. Stepping on the pressure plate triggers a fireball to be shot at you, but it remains sunken. Stepping on it a second time resets it, so only each odd-numbered time you step on it will throw a fireball. The pit after the fireball trap drops you downstairs, so time it right and go up the stairs to an isolated part of the Crimson Tower (I call this the Crimson Tower Outpost, but it's also known as the North Talon Tower). A copy protecton is triggered as you go up the stairs.
The beautifully decorated halls are already an indication that you must be getting close to your goal. Mages in this area are quite powerful and can cast spells like Magic Missile and Fireball, but are not hard to kill. One of them drops a Crimson Ring, which you should pick up. A couple of levers in this area turn off the invisible teleporters that can get you lost pretty quickly.
In the northwest corner of the level is a niche that transforms anything you put in it into a glass sphere. You need three glass spheres, so if you used up any of the three you found earlier in the game, you can use the niche to make up for the difference. Either way, once you have three glass spheres and the Crimson Ring, there is nothing more to do here, so go back downstairs to access the Crimson Tower proper.
Crimson Level 1 Access
From the Crimson Outpost, cross the pit and the pressure plate (quickly to avoid the fireball) so you are back at the main area giving access to the Crimson Tower. At the south end are two pressure plates leading westward to what looks like a dead end. Drop something on both pressure plates to open up the passage.
Priests guarding the stairs to the Crimson Tower greet you with a fireball. You should respond in turn using spells of mass destruction. Once they are out of the way, go upstairs to Crimson Tower Level 1.