When the Hero enters the settlement Shetcombe Farm, they'll find the first page of a journal that will lead them to Sandstone Cavern. The Sunken One can be found inside the cavern after they have solved what happened to Slythe and he needs to be killed in order to be complete the quest.
|4||Common||100||30||Freezing Touch, Atronach Frostbolt||00009EF6|
|8||Greater||200||45||Atronach Frostbolt, Shocking Touch||00009EF7|
|13||Greater||300||60||Shocking Touch, Atronach Lightning||00009EF8|
|20||Greater||450||90||Atronach Frostbolt, Freezing Touch||00009EF9|
- The Sunken One might be a reference to the literary works of H.P. Lovecraft.