This mystery can be found on the eastern coast of Eurvicscire, southeast of Picheringa.
Where to Find the Fisherman’s Wife at Picheringa
When you arrive at the scene you’ll find a man who has been crushed by a large rock. Use Odin’s Sight to highlight the note beside him, and interact with it to read the contents. You’ll soon discover that this man was most likely part of a gang of thieves and murderers, but was hoping to leave and was killed for it.
After reading the note you’ll automatically loot a ring which the man was hoping to give to his wife. To complete the mystery you’ll need to speak with his wife in Picheringa, a small village to the northwest. The location of the man’s wife is marked in the screenshot below, in the southwest of Picheringa. When you speak with her you’ll have the option to lie and keep the ring for yourself, or give the ring to her as her husband would have wanted. Either way, after the conversation the mystery will complete.