Captured by sirens, Jurek struggles to save his fellow prisoners before they’re devoured. He has little time. His memory is vanishing from his mind, a poisonous effect of the magic that saved his life. With a past steeped in tragedy, it should feel like a blessing. Instead, it's a curse unraveling everything he is. When he strikes a bargain with the sirens – three impossible tasks in exchange for everyone’s freedom – help comes from someone he least expects and whose motives he doesn’t dare trust. Ava, youngest of the billow maidens, has become an unwitting traitor in a war between the gods. Her sisters want her to pledge fealty to the ruinous Eldingar. Her brother, the Guardian of the Fathoms, wants her to act as his spy. And then there's Captain Jurek, a landweller whose fierce heart and haunted blue eyes mean more to her than they should. He doesn't trust her, but without her help he won't survive. As the old gods make their move against the world that betrayed them, Ava must determine whose side she's on. But no matter what she chooses, it'll mean death for someone she loves.