SELYE'S INVESTIGATION

This quest unlocks after “the new campsite”, only in Selye’s route, for obvious reasons, regardless of your choice.
Snow will deliver you a message very ssssstraight to the point from the naga, go see him to automatically start the quest (you may need to leave and enter his room a few times to trigger the previous dialogues with him first).
While it is some unique part of the game, and rare time with Selye, there is no fight or actual choice to make in this first part of the investigation, so it is a free 200 coins and level up point.