Eye of the Beholder 2 Walkthrough - The Azure Tower, Level 4
After going up the stairs from Level 3, you will have your first encounter with aerial servants. They are tough, but give a lot of experience. After killing the couple of aerial servants that attack you, go through the teleporter.
After another aerial servant encounter, you will reach a large room. At the north end is a statue that will open the east door upon request. He will tell you that you are not ready, unless each of your part members have a polished shield equipped, but will open the east door anyway if you ask.
This does not mean you can get away with not having all six polished shields, however. In the room to the east, you have to hang all six shields on the designated walls in order to open the north door. After doing this, make sure you take them back, and equip them.
A word about the six polished shields before we go on. In Greek mythology, Perseus managed to defeat Medusa the Gorgon, whose gaze turned people to stone, by seeing her reflection in his polished shield. In the labyrinth you are about to enter, the polished shields provide protection (but not immunity) from the petrifying gaze of the medusae. In addition to this, casting improved identify upon them reveals them to be medusa shields. When equipped, apart from granting protection from petrification, they give an armour class bonus of 3 (i.e. they are as good as +3 shields), except to mages who can't use them.
The Medusa's Labyrinth
After opening the north door and re-equipping the medusa shields, head north. There is a room that contains a few medusae but is otherwise empty.
Head southwest, where you should find and pick up a tooth key along the way. Continue southwest, as the passage bends northeast and then southwest again, until you reach the long north-south corridor at the west end of the level.
This corridor contains a spinner, and at the end is a one-time teleporter that will take you back to the south end of the corridor. If there are any medusae here, you can use them to observe the effects of the spinner and invisible teleporter.
Continue north, and then turn east. The button on the wall opens the two doors here; a horde of medusae pour out from this room, so take a couple of steps back so you don't get surrounded.
After killing the medusae, proceed through the north exit from the room, and continue north to a dead-end where you will find a mage scroll of invisibility 10' radius, and the stone dagger.
From the location of the stone dagger, go south back to the main corridor, then head west for a couple of steps and turn north. Follow the corridor east all the way, and then south, where you will reach the centre of the labyrinth.
The Medusa Hub
At the south end of this room is a plaque telling you what you have to do here. There are four pressure plates in this area, and you must use the medusae (which are continuously spawned) to weigh them down. This is achieved by luring them onto the plates, casting Hold Person (Cleric Level 2) or Hold Monster (Mage Level 5), and then closing both doors around the plate, in order to trap the medusae even after the spell wears off. Once all four plates are weighed, the northeast door opens.
A special case is the southern pressure plate, which you must leave for last (otherwise you get stuck in the middle and have to kill one of the medusae to get out). There are four doors around this plate; you must close at least three (W, S and E). If you don't close the north door, the medusa will be trapped in a three-tile area, meaning she will occasionally step on the pressure plate. As a result, the northeast door will open and close continuously.
With all four plates weighed down, head through the northeast door (not the one you came from) and follow the corridor to a small room. Here, among lots of bones, pick up the Hilt of Talon, and a Mage Scroll of Flesh To Stone. A brick on the lower part of the north wall opens up a passage to the east. At the end of this passage, use a tooth key on the skull on the wall to open the door.
This final area keeps spawning aerial servants. So if you aren't in a hurry, and would like to raise your Mage to Level 12 in order to cast Disintegrate or other Level 6 spells, this is a good place to gain experience.
There is a banner in this area that will drop a mage scroll of cone of cold round the corner when you examine it.
Ultimately, what you have to do is step on the pressure plate in the middle of the southern part of this area, at which point Dran will trap you like a fly in a jar and drop you to Azure Level 5. Before you do this, however, be warned: the next level is short but very tough. Make sure you get some rest and have all the spells that will help you in battle. Read the beginning of the Level 5 walkthrough for spell suggestions.