Geolus tasked you to look for Investigation Team Scholar Lepios. He left for the Contaminated Swamp and never returned. You found Lepios. He suffered an injury travelling to the Swamp and could not complete his work. So he asked you to carry out the task in his stead. To do so, he gave you the antidote crafted in Sanctum. You applied the antidote in the Contaminated Swamp and eliminated the Poisonous Bubblegut. The cause of the contamination was a poison Kato discovered in Sanctum Then Kato fled into the forest and the poison transformed him into the Poisonous Bubblegut. He thanked you for rescuing him.