To start this quest, speak to Barry O'Neil in Darkdale (X:236 Y:342).
FIGHT: Afterwards talk to her son Burt O'Neil (standing next to her) and give him 6 Burial Bands. He will give you a String of Rings. This will start a fight against three Diabolical Ghost Head (level 24 non-elemental Wizard) and three Ghost Head (level 22 non-elemental Wizard) that both cast Chant of Impure Thoughts. This battle must be soloed, you cannot have a team although it is beneficial for another person to buff you before you enter the battle.
After completing the battle a cutscene will follow and afterwards you will obtain your rewards.