Speak with Darkcaller Yanka in the Ruins of Lordaeron just outside the entrance to Undercity.
Well met, <class>.
Hallow's End is a time for celebration and reflection, though some have no idea why. The burning of the Wickerman in particular is a mystery to many outside the Forsaken.
Travel to the Ruins of Lordaeron above Undercity and speak to Darkcaller Yanka. She can tell you more about the Wickerman ceremony.