In a small inn (the more remote the better), a man turns up dead. There are no wounds on his body what-so-ever, and he aboslutely reeks of garlic.
The man died of a curse that forced him to eat a clove of garlic a day or suffer the penalty. This gets really interesting if the body somehow appears on top of a someone the villagers are suspcious of.
The ruling family depends on some magical artifact or place to secure their right to rule. A monarch isn't considered legitimate until he or she has been "accepted" by the artifact or place, whatever that might entail. It is also possible that some one else, not of the ruling family, could be accepted as the legitimate heir... A fact which the monarchs would like to keep secret.