A One-Round Introductory Living Greyhawk Onnwal Regional Adventure
From the introduction:
For brand new characters of level 1.
Obelstone – a dark tower that is a prison complex said to sap the will and steal the mind of all who are brought within its confines. As prisoners of the dread Scarlet Brotherhood you are to be its next victims – unless escape is somehow within your grasp.
Note: This must be the first Living Greyhawk scenario you play with your character.
Based on ONW1-01: Escape from Scant.