Having long wondered what lives beyond the ice shelf, nineteen-year-old mermaid Ersel learns of the life she wants when she rescues and befriends Ragna, a shield-maiden stranded on the merfolks fortress. But when Ersels childhood friend and suitor catches them together, he gives Ersel a choice: Say goodbye to Ragna or face justice at the hands of the glaciers brutal king. Determined to forge a different fate, Ersel seeks help from the divine Loki. But such deals are never straightforward, and the outcome sees her exiled from the only home and protection shes known. To save herself from perishing in the barren, underwater wasteland and be reunited with the human shes come to love, Ersel must try to outsmart the God of Lies.