Ja-un’s forced by his abusive family to take his cousin’s place as a ritual sacrifice meant to end the plague. On the way to his death, Ja-un recalls the only friend he had as a child—a little snake named Sosa. When he calls its name, the demi-god Sosa, who has loved Ja-un through all his lifetimes, appears and spirits him to safety. Despite Sosa’s affection, Ja-un’s trauma and the torment carried from his past lives linger, and not even Sosa may have the power to protect what he cherishes most.