This quest begins once you have completed Mistress of the Iron Wood. After being freed by Hyrrokin, Eivor sets out to find Aegir’s lost cauldron, to provide it as a gift for the great feast of Suttungr.
Where to Find Aegir’s Cauldron
To begin the search, travel to the site where the cauldron was stolen, just west of where the quest begins, and north of the Serpent’s Tree. Here you’ll find what remains of an ambush, including a cart wheel, an upturned cart, and a broken tree. Use Odin’s Sight to highlight each of these items of interest, and examine them. You’ll then be able to track where the cauldron was taken by following the path south, with more broken trees along it. The tracks will eventually lead you to Skrymir’s Mitten, which you’ll need to enter and follow the root system within.
Exploring Skrymir’s Mitten
The path through the mitten will be fairly linear at first, leading to a gate with the cauldron behind it. Once you’ve seen the cauldron, turn around to see a new path which has opened up to the southwest. Go through here and kill the Jotnar, then move the barricade to the north to go deeper into the mitten. Loot the treasure chest in the next room, then go through the door and kill all the other Jotnar in the room to the north. You’ll have the element of surprise here, so make the most of it and attack the elite units with a headshot if you can.
Once all the Jotnar in this room are dead, turn your attention westward and climb the scaffold to the key above. Once you have it, continue northward and kill the two Jotnar here. Slide under the hole in the wall and view the cauldron between the wooden branches to make it smaller. You can now collect the cauldron and complete the quest.