Watcher's Keep Elemental Level

Elemental Level is the 2nd level of Watcher's Keep.

Guide

 * As soon as you arrive on the Elemental Level, the Chromatic Demon will speak to you. It will agree to open the portal to the next level, if you free it from its prison. You have no choise but to accept.
 * Enter the Fire Library to the northwest. In the passage to the Air Chamber, you will meet an imp who will tell about the area and will give you some hints.
 * Surrounding the central chamber are four libraries, each representing a different element. In each library, you will find a note that will tell you to destroy the guardian of one of the chambers.
 * Enter the Air Chamber and turn the wheel to start the giant fan. Several Air Elementals will appear to attack your party. Defeat the Guardian of Air and you will receive the Air Scepter.
 * Use the Air Scepter to open the two doors off of the Air Library: one to the Air Chamber and one to the Slime Chamber. Use the Key in the Slime Library to open the other door to the Slime Chamber. Enter the Air Chamber and click on the wheel to turn the fan on high to blow the toxic vapours out of the Slime Chamber. Enter the Slime Chamber and defeat the Giant Snake to find the Slime Scepter.
 * Use the Slime Scepter to open the door from the Slime Library to the Ice Chamber so that the toxic vapours blow into it to make the Ice Golem vulnerable. Defeat the Ice Golem to get the Ice Scepter.
 * Turn the fan in the Air Chamber back down to the low setting and then use the Ice Scepter to open the two doors between the Fire Chamber and the Ice Chamber. Lead each of the four Fire Elementals into the Ice Chamber where they will freeze and will not be able to regenerate. Kill the Fire Giant in the Fire Chamber to find the Fire Scepter.
 * Go to the center of the area and click on the Chromatic Demon's prison with all four scepters in your possession. The demon will be freed and will attack your party. Each of his different forms has a different weakness which is explained in the four notes you found in the Libraries.
 * Once you have defeated the demon, take the Portal Key from its body and step into the portal to the 3rd level.

Guardian of Air

 * Air Scepter

Giant Snake:

 * Slime Scepter

Fire Chamber

 * 3 Potions of Fire Resistance

Sources & references

 * Baldur's Gate II section at Mike's RPG Center