[apesmom]

The first prequel to the Valkyrie Bestiary series is free. It pre-dates the MCs of the series but adds depth to some peripheral characters and world history.

The Last Door to Underhill (Valkyrie Bestiary #0.1) by Kim McDougal

Spoiler:

In the last hours of the Flood Wars, a fae princess makes the ultimate sacrifice to save the human world. Leighna, a refugee of the war, returns to Underhill with a true demon on her heels. With only her old arcane arts tutor and a strange dryad as company, she must close every door between Terra and Underhill. But can she find the strength to abandon her homeland and become a permanent exile?

The Last Door to Underhill is a Valkyrie Bestiary tale, set in the chaotic days after the Flood Wars, when magic is the only rule of law. It takes place about fifty years before the events in Dragons Don’t Eat Meat.