“Zulia has sought refuge deep within the mysterious inner chambers of the Temple of Eluvium; and you’ll need to follow her. Lost in her rage and fear, Zulia has no desire to be found, and has turned the Temple’s preternatural guardians against any who dare enter. Should you manage to survive the onslaught of the giant Augerites, powerful fiends, and twisted harpies, you’ll need to face Zulia herself—as the newly crowned Queen of the Hive.”
When the patch is live, Halloween events will also begin in the game; expect “creepy candy consumables” and the “Ghoulish Gift Box,” plus a Halloween-themed vendor where you can buy even more seasonal stuff.
Source: Official site