Before the county of Corvis, there was the Wizard Corvus. Thirteen hundred years ago, a mad powerful wizard had an estate in the area that became the county of Corvis. Over his 800 year span, he created thousands of magikal items of various types and power level, some of which survive to this day.
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.