The cast of characters you meet and interact with in Baldur’s Gate 3 are some of the highlights of the entire experience. Odds are most, if not all, will intrigue you in some way, encouraging you to learn more about them and to help them with their personal goals. Like plenty of RPGs, your companions in Baldur’s Gate 3 all have unique companion quests that are unique to them that unlock at different stages of your adventure and relationship with them. Each one asks something different of you, with Karalach being one of the most unique and difficult. Karlach is in desperate need of a very rare resource and asks you to collect something called Infernal Iron. If you’re at a loss for where to find it, here are the places to look.
Where to find Infernal Iron
There are three known pieces of Infernal Iron in the early game.
The first, you can find in the Blighted Village by entering the basement of the northern house. You can enter by somehow opening the locked door or getting in through the ceiling. This is also where you pick up the Masterwork Weapon quest. From the room with the forge, climb the ladder and interact with the locked chest. You, or a companion, will need to pick it to open it up and loot the Infernal Iron.
Our second piece is the Goblin Camp. Make your way to the Shattered Sanctum to the north behind Dror Ragzlin’s throne. There’s another locked door here you’ll need to bypass to enter the treasure room littered with valuables, including one piece of Infernal Iron.
The last piece of Infernal Iron we know of is the hardest to get to. The difficult part is just getting where you need to be, which is the Zhentarim Hideout. This is north of the Blighted Village up Risen Road where you come across a place called Waukeen’s Rest. The house will be on fire the first time you arrive, but instead of helping the soldiers, go through the alleyway to locate a house with some crates blocking the door. Get the crates out of the way and head inside to meet Salazon, who isn’t too happy to see you. You need to use Detect Thoughts to read his mind and get the password to avoid a fight and collect a key to the basement. Go down and use the key to unlock the hidden staircase finally leading you into Zhentarim Hideout.
On the north end of the hideout are two locked doors, but the one you need to break into is the one on the right. Behind it is a chest with the Infernal Iron.
Once you reach Act 3, Infernal Iron becomes a more common drop from the Iron Watcher enemies.
You can spend Infernal Iron with Dammon to repair Karlach’s heart as part of her quest, but only once per act.