The Knight and the Butcherbird by Alix E. Harrow

In this dystopian fairy tale from the bestselling author of Starling House, a small town’s storyteller struggles to protect a local demon from the knight hired to kill it.

Hundreds of years after the end of the world, the Appalachian community of Iron Hollow finds itself beset by demons. Such horrors are common these days in the outlands, where most folks die young—if they don’t turn into monsters first.
When a legendary knight is summoned to hunt down the latest unearthly beast to haunt their woods, the town’s new oral historian, Shrike, has more reason than most to be concerned. Because that demon was her wife. And while Shrike is certain that May still recognizes her—that May is still herself, somewhere beneath it all—she can’t prove it.
Determined to keep May safe, Shrike stalks the knight and his demon-hunting hawk through the recesses of the forest. But as they creep through toxic creeks and overgrown kudzu, Shrike realizes the knight has a secret of his own. And he’ll do anything to protect it.