A One-Round Living Greyhawk Highfolk Regional Adventure
From the introduction:
The Guildsmen of the High Art have been busy these last two years. They’ve moved into a new Guildhall and rumors say it is haunted. Whispers of keys, both magical and musical, and even the discovery of something called a spellpool abound within the new halls, and now beyond them.
This adventure is especially for arcanists and their investigative allies, APLs 6-12.