This quest is acquired from Scout Harding at Basin Floor Camp. Her friend, Grandin, has gone missing. As he was last seen north of the camp, she asks you to search there first. Once you reach the highlighted area you will be able to search for a special item; a note pinned to the ground by a sword. From here, head north east until you find another note pinned to a dead body. Next you’ll come across some burnt corpses. Continue along the trail until you reach a cave entrance. Inside you’ll find Grandin, who has become possessed by a rage demon. At this point you can choose to let him go or fight him. Whatever you choose, once done, return to Scout Harding to complete the quest.
Note: The Rage Demon that you will have to fight if you choose to fight Grandin is much more powerful than a regular Rage Demon. It has the same abilities, but inflicts more damage and have a large amount of health.