Back to Skellige
Enter the cave along the road between Arinbjorn and Kaer Muire. You’ll also be directed here if you’re looking for the Bear School Gear. Once you’re in the cave the Enhanced Ursine Boots Diagram can be found in a chest near to the boat.
When you enter the cave you’ll hear the sounds of farting coming from three large trolls. It must have been something they ate! When you enter they’ll immediately attack. There’s no way of exploring the cave without killing them first. Once you’ve defeated them the quest will end.