The chest with the first evidence is in a small alcove on the sleeping quarters (not the one with Nettie, the other one). At the moment you have to bash the chest open, lockpicking does not work. There you find a location. Go there, fight the enemies and look for a second letter (you have to search that map a bit). Then go back and you can confront Kagha.
Last edited by fylimar; 16/03/21 07:59 PM. Reason: typo
