Head to the lone island south of Fyke Isle (north-northwest of Frischlow) where half a ruin stands. Once you near the campfire between the standing structure, about 5 drowners will appear. Deal with them, then loot one of the bodies nearby for the blood-smeared notes and read it to start the quest.
There are a number of chests here with a total of 12 random diagrams as well as a chest with the enhanced wolven armor diagram. However, the chest you want for this quest is in a submerged area with another chest (not the one with a hole in the ground). It's just east of the standing structure and where more drowners are circling in the water. One of these chests contains the Deithwen sword and will complete the quest.
Journal entry Edit
- Geralt happened across an intriguing note written by someone who, first of all, clearly suffered from a poor memory, and, secondly, had hidden valuables somewhere nearby...
Note to self:
- Small isle with ruins or a bridge built of red brick - that's the spot. Traces of a camp left on the isle.
- Will need to dive down among the submerged ruins. Chest visible among them.
- The witcher followed all tracks, investigated all evidence and peered under every rock until he finally found the chest and within it - treasure.
- Read the notes you found.
- Find the sunken treasure chest using your Witcher Senses.