Note: This content can be accessed only if you purchased The Exiled Prince DLC pack.
This quest is available only if you did the quest 'Duty' earlier which in turn also means you have access to this Premium Content. Head over to the Chantry and head up to where Sebastian is located. Read The History of the Chantry: Chapter 2 then talk with Sebastian. While you're in the Chantry head to the northern area and open the chest - complex in the western room for Andraste's Wisdom ; in the south-western room you will find merely a crate .
Head to the High Estates in Hightown where you can find a rubble in the corner near a guard as well as a crate in the section over. Enter the Harimann Estate when you are ready.
Head up the stairs and into the southern room to find a barrel . From here go north to view a mini scene then head into the southern room for another. Read Flora Harimann's Diary then open the nearby chest for a Mail Undertunic , an upgrade to Sebastian's armor. Continue your search east and up a set of stairs, then check The Vael Family book on the desk.
In the next room east you'll find quite the scene, ignore it and read more of Flora Harimann's Diary . Open the chest - complex nearby then backtrack to the hall before this area. Go into the southeast room to find a book on Divine Justina V , more of Flora Harimann's Diary , and a chest . Head south into a storage area to find a sack then go east to the objective. After the brief scene defeat the Desire Demon and loot her for Fade's Fury . Don't miss the flint company mercenary corpse on the ground holding the Starkhaven Longbow , it's a gift for Sebastian.
Enter the Underground Passage and head east until you are ambushed by a Rage Demon and it's Shade underlings. Defeat the spirits then check the rubble before progressing further east. In this large room you will face a great opponent in a Revenant. Head up the stairs to the east after you take out the Revenant to find some rubble then make your way north to a corpse and more undead. Once they are dispatched head west to find more rubble then go north.
In a small area up the steps is a chest - complex and further north is yet another Revenant and an Arcane Horror. Up the steps to the west is a chest - complex and notes on The Demon's Gift . In the room before the final room is some rubble , loot it and continue north to the exit. After the talk with the Desire Demon you are thrust into battle. Take out Lady Harriman as soon as you can, she is a powerful Blood Mage and can tear through your ranks. After she goes down take out Allure to all but end the fight.
Loot the bodies for Allure's Crook then speak with Sebastian back at the Chantry to finish the quest.
Confront the culprit behind the Vael family's murder ( The Exiled Prince DLC).