This quest is not available in game.
Speak to Aelthalyste in the Undercity.
This isn't the place for you, <name>. You should head to the War Quarter in Undercity as soon as possible. Aelthalyste has called all her priests and priestesses there as soon as they are ready. It's time they learn more about their power and how to harness it.
She will not tolerate tardiness or excuses, so you'd best be on your way.