After the murder of her husband and the fall of his empire, a mermaid and her plague doctor companion escape into the wilderness. Deep in the woods, they stumble across a village where children hunt each other for sport, sacrificing one of their own at the behest of three surgeons they call "the saints." These saints play god with their magic, harvesting the best bits of the children for themselves and piecing the sacrifices back together again.

To save the children from their fates, the plague doctor must confront their past, and the mermaid must embrace the darkest parts of her true nature.