Hood (#7 in The Hyllis Family Stories)

This tale of healers with “talents” is the seventh in a series of stories that follow the psychically talented members of the Hyllis family.
Hundreds of years after a plague induced apocalypse collapsed civilization back to iron and horsepower, the Hyllises have a genetic tendency to inherit “talents”
such as telekinesis, teleportation and telepathy. Though they aren’t powerful talents, they help the Hyllises diagnose and treat the underlying causes of many illnesses in their role as healers.
In this book, their town of Clancy Vail is struck by the plague. In order to save thousands of lives, they must master and use the knowledge of epidemiology contained in their copies of the ancients’ books.
Meanwhile, Tarc sets out on a journey to their original home town, hoping to get the money they’re owed by people there. On the way there, and after arrival, he encounters troubling rulers, old friends, and determined enemies.