I stayed up late to finish this book. I was surprised by that, because I didn't think I would be engaged with the book during the first 1/3... I would recommend it.
Ista is a 'dowager Royina' who has been touched by a god. There are several interesting variations on fantasy themes that are explored and expanded skillfully. Five gods, mother father son daughter and Bastard, with the mischievous Bastard getting the attention here. Magic flows from demons, which start as elementals and gradually absorb qualities and skills from their hosts, often animals at first, jumping to a new host when the old one dies. They can be controlled by a person for a long time, creating sorcerers, until they loose control.... The gods get involved in human affairs by giving abilities and directives to people. Ista has had a bad experience in the past with this, and now resists the Bastard trying to draw her in again. She starts on a pilgrimage and ends up in a border fortress, trying to unravel her host, his comatose brother, and his young seemingly naive wife.
This book won the Hugo and Nebula awards for best novel.