The Stag and the Horse - Chant of the Flooded, #1

Once, Ainara lived alongside her clan, her people. Now, that clan is no more. In an unforgiving world, Ainara's people mysteriously vanished in a heartbeat, and she now lives only to avenge them and put their souls at peace. The culprit is obvious: it was the Zaldi, the demon horses. But as she undertakes her quest to avenge her people, she begins to learn it may not be so simple to succeed; and she's willing to do anything in exchange.
Even if it means involving herself with so-called demons. Even if it means she will do the unthinkable, and face off against other humans.