Rilis, one of my champions, was exploring the map. She enters in a inn and got the quest to kill rats. She headed to the new spots, killed the rats, got the corpses and went back to the inn. But no complete quest message was appearing, I got the "already visited message" and the inn stay yellow.
As I was able to end the rats quest in another 2A game with my sovereign, I decided to move my sovereign, Unuchr, toward that inn. When my sovereign arrived, I tranfered the rats corpse from Rilis to him and he enetered the inn. This time, the message appeared and he got the reward.
Here is a savegame just before my sovereign got the corpse and enter that inn.
Look at Rilis. She has the dead rat. Try to move her into the inn, that won't work. Give the rat to the sovereign and move him into the inn, you will got the ending quest message