Vague predictions of the future and lead one to adventure.
Saints and Sainthood: The inside story on the ascended
“Dreams are the only reality” suggests some of the ancient manuscripts. Dreams and the dreamers often reveal secrets long forgotten, or dreams can hide the truth only to make it resurface decades or even centuries later
Herbalist in the group mistakes one plant for another and mistakenly poisons the group. Not to death, but pretty darn ill with recurring symptoms until the cause and cure are realized. (Local people may be able to help rather easily. "You ate Dragon's Rot you fool, looks and smells just like mint except it has these small thistles on the root. Only grow in the Hornwood Forest, that must be where ya got them. Eat this and you will feel better in 4 hours."