Note that this quest is not available until Act 2, even if Duty is completed during Act 1.
Speak to Sebastian in the Chantry and agree to help. (There will be a funny exchange with Varric after Hawke's first dialogue choice if he's in the party). Then travel to Hightown and enter the Harimann Estate. Sebastian will be locked into the party from this point forward. There are three chests with Complex-ranked locks in this quest (30 Cunning to open, 150 XP each).
You will encounter enemies who employ spirit damage, thus a Rune of Spirit Warding in companion armor will keep them safe from most of the damage. The design is available from Mage Goods in the Gallows as soon as Act 2 begins. All enemies have some form of elemental immunity on Nightmare difficulty, but the nature immunity of Undead and Revenants is counterbalanced by a weakness to spirit damage and vice-a-versa in the case of Shades, Desire Demons, and Arcane Horrors. All demons and undead are weak to electricity, save for Rage Demons, who suffer normal damage. They are immune to fire and weak to frost. Additionally, Revenants are immune to frost, but it works well against every other enemy encountered here, so an Elemental mage is highly recommended in spite of these resistances.
Your journey through the mansion will pass without incident until you reach a cutscene. Collect the Mail Undertunic from the nearby chest (armor upgrade for Sebastian). Before you continue, take a detour to the east section of the mansion for an amusing cutscene and a complex chest. If Isabela or Varric is in your party, they will have some amusing comments. Merrill also has a comment if Isabela is not present.
As you approach the waypoint marker, a cutscene and battle with shades and a Desire Demon will follow. Defeat the Desire Demon first to keep her from buffing the shades, then focus on stunning them before taking them down one or two at a time. The Starkhaven Longbow (gift) can be picked up off a nearby dead Flint Company mercenary. Picking it up activates the companion quest The Starkhaven Longbow, which can be completed after you return to the Chantry.
Enter the Underground Passage to continue the quest. The layout of these ruins is similar to the "mining caves" from Blackpowder Promise, Wayward Son, and similar areas, only with more ominous textures. Thus you can fall back to the same chokepoints to corral the enemies. In the tighter chokepoints they will not be able to get ahead of each other to even attack, making them easier to defeat.
The first battle features a rage demon and numerous shades. For some ease, head downstairs to draw a few of them plus the rage demon, then back upstairs to take them out as they come. Stun the rage demon and defeat it before it can "backstab" too much. The remaining shades will spawn down below, so engage them when you are ready.
Your next fight is with a Revenant and a selection of corpses. Pull the Revenant into the previous chamber without aggro'ing the corpses for an easier encounter, then take them out, prioritizing the archers when they appear.
Down some steps to the north, two more rage demons attack at once. Retreat back upstairs and fight them from just over the threshold. One will effectively block the other's advance, allowing them to be taken down one at a time without interference from the reinforcements down below. Beyond them is a Revenant and an Arcane Horror, but they do not have to be fought together. Lure the Revenant to the previous chamber first and defeat it, then stun and rush the Arcane Horror before it can unleash a single AoE. After the battle, go up the stairs to the west to find the Codex entry: The Demon's Gift and a complex treasure chest. Before you enter the final room, don't forget to pick up 4 (exact amount varies with level) from some rubble in the corner.
Keep going and you will find Allure, a Desire Demon, and Lady Harimann, who is a powerful blood mage. After some dialog, you will have to defeat them. They will be joined by four shades. You can lure them back to the previous room and single-file them to be killed one at a time, or a little further so Lady Harimann and/or Allure give up their pursuit. Lady Harimann is easy enough to kill with a quick stun and four-on-one assault, and Allure doesn't have the durability of other "commander" type enemies, so you may not even need to retreat. Simply kill Lady Harimann and the rest of the fight should fall into place around the companions you brought.
Return to the estate via the nearby exit. You will have a bit of dialogue with the daughter, Flora Harimann, who apologizes profusely and swears to make amends for everything her family did, including helping Sebastian retake Starkhaven.
Return to the Chantry and speak to Sebastian to complete the quest.
During the conversation with Allure and Lady Harimann:
- "I wouldn't betray my friends"
- "I do like power"
- "Die, fiend!" (Attack)
Choice 2 (If you did not attack Allure):
- "That's a good point."
- "Don't listen to her..."
- "Die, fiend!"
Dialogue with Flora Harimann:
During the Final conversation back in the chantry:
- "That's a good question"/"What do you want to do?"/"Listen to your heart"
- "You must take back your land." (Eliminates Flirt option.)
Other dialogue choices here seem to have no impact.
- Sebastian joins as a permanent companion.
- If the item was picked up, the companion quest The Starkhaven Longbow will activate.
- Mail Undertunic
Companion armor upgrade
+2% critical chance - Sebastian's armor upgrade (+2% Critical Chance)
- Fade's Fury
Requires: Weapon and Shield
Damage: 25 physical damage
(47 per second)
+5% critical damage
+3 spirit damage across 2m - loot Desire Demon
- Allure's Crook
Requires: 34 magic
Damage: 35 spirit damage
(48 per second)
+5 mana/stamina regeneration rate - loot Allure's corpse
- 11 from Sebastian
- 1000 XP(quest completion)
- Due to game auto-assigning attribute points until a character is officially recruited, Sebastian's Cunning will likely not be high enough to open the locked chests within the house or ruins. The building remains open throughout Act 2 however, and it is possible to return later to empty them. There's no further dialogue with the surviving Harimanns, so if you were able to loot everything there's no need to return later, be it day or night.
- If you have The Black Emporium (DLC) installed, you may use a Maker's Sigh potion before doing the quest.
- You can also accept the quest to officially recruit Sebastian but delay entering the Harimann Estate until your level is about 15-16. This will provide Sebastian enough attribute points to reach the Cunning threshold of 30 (There are no Master-ranked chests in the estate).
- Certain outcomes of Night Terrors will be reflected in the dialogue with Allure. If you ask it about a deal ("I do like power..."), and if Isabela betrayed you, it will say, "Just make sure whatever it is doesn't disappear this time. Bloody demons with their promises and their stupid imaginary boats." If you select "I'd never betray my friends," it will respond, "How loyal were your friends to you? Everyone has a price. Everyone wants something." Oddly enough, even if you have yet to enter the Fade, Allure will respond in the same way. This implies that this quest was originally written with the assumption that Night Terrors would have already been completed (or the demon could be referring to Bartrand, but calling him a friend would be generous, to say the least).
- pc (1.04) Before and after the conversation with Allure and Lady Harimann, the screen goes black and the "Loading..." message pops up. To proceed with the quest you may simply press Esc as soon as you see the message, however this causes you to miss some dialogue.
- pc (1.04) A full workaround has been discovered however that allows you to not miss anything (see also Faith in Act 3 for how this bug is "game-breaking" to that quest). You must enter your Dragon Age II program folder and temporarily delete the patch folder under GameFolder\Addins\da2_prc_drk\module as that's where the interference lies. Then, after completing Repentance, restore the patch folder. The source of this information is at Freezing issue in The Exiled Prince DLC