“ A magical stave with two distinct uses. One end is a healing stick, which can heal some quite serious diseases, the other half can be used to inflict those diseases on other people.”
“ A terrible affliction spreads through the land: A disease, highly contagious, which makes its victims mildly ill, but then permanently paralyzes the vocal cords. Dozens of reputed cures and protections are sold in the marketplaces, which gradually grow quieter and quieter...”
“ The PCs are accosted in a major city containing at least one famous fortuneteller / prophet of the future. They are informed that their as-yet-unborn child will (insert terrible evil), and that, although they are very sorry, the PC must be executed to keep this from happening.”