prologue
Follow Pieter and train.
Decide whether to leave before dusk or wait with him.
Only what a source states. A quest with nothing listed is a quest whose rewards are unpublished, not one that gives nothing.
This is a published supply line for a skill manual, and so unlocks a skill for purchase. Getting the book costs no skill points and no training time; buying the skill at a shrine afterwards costs both. Where a manual has more than one source, this is one route to it rather than the only one.
How the quest ends is the expensive part: leaving costs one segment and keeps the prologue's side quests open, while waiting with Pieter costs five and starts the next main quest immediately. That is the largest single published segment cost in the game.