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companion 1 min read · Updated July 7, 2026

BG3 Karlach Companion Quest Guide: Infernal Engine, Dammon Upgrades & Best Ending

Complete BG3 Karlach quest guide. How to recruit Karlach, all Infernal Iron upgrades, where to find Dammon in each act, and how to get Karlach's best ending.

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Act 1: Recruitment + First Upgrade

  1. Recruit Karlach on the Risen Road (north of Blighted Village). Kill Anders and his fake paladins.
  2. Bring Karlach to Dammon at the Emerald Grove. He examines her engine: it’s overheating. Needs Infernal Iron.
  3. Give Dammon 1 Infernal Iron → First upgrade: Karlach can touch people without burning them. You can now kiss her.
  4. Wyll’s choice: Mizora orders Wyll to kill Karlach. Refuse. Karlach and Wyll can coexist.

Act 2: Second Upgrade

Find Dammon at Last Light Inn (barn area). Give him the second Infernal Iron → engine stabilizes further. Karlach is cooler (literally). Romance progresses. Additional dialogue options unlock.

Act 3: The Engine’s Fate

The engine cannot be fully fixed. Karlach faces death: return to Avernus or die on Faerûn. Key options:

  • Go to Avernus with Wyll (he volunteers if he’s the Blade of Avernus)
  • Go to Avernus with you (if romanced)
  • Stay and die (sad but poetic ending)
  • Become a mind flayer (sacrifices herself to save Orpheus/you)

Best ending: Go to Avernus together. The epilogue shows Karlach alive, fighting demons, with a lead on a permanent fix for her engine. Hope exists.

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Frequently Asked Questions

Where do I find Infernal Iron for Karlach?

Act 1: Dror Ragzlin's treasure room (Goblin Camp), Stonemason Kith's stash (Blighted Village basement). Act 2: Various chests in Grymforge. Act 3: Sold by merchants in the Lower City. You need 2 pieces total — one per upgrade.

Where does Dammon go in each act?

Act 1: Emerald Grove (tiefling blacksmith). Act 2: Last Light Inn (barn/stable area). Act 3: Forge of the Nine (Lower City). If the tieflings die in Act 1, Dammon dies and Karlach can never be upgraded.

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