On the day of the Crimson Festival, Livia wakes from another nightmare about a serpent eating a songbird. Her friend, Jason Eriksson, comes to retrieve her, and she shares her concerns over the nightmare, knowing that the serpent is meant to represent Erik Bloodsinger, the Ever King. Jason worries over her but eventually ushers her out of her room to share in the festivities.

Livia and Jason join the rest of their family and friends to send off the kings and queens of fae folk for their yearly council meeting. Amidst the bustle, Livia feels a sense of foreboding when she looks at the Chasm, the barrier that divides her people (the earth fae) from the sea fae—Erik Bloodsinger’s people. Along with Livia’s friend Mira, Sander (Jason’s twin brother) watches the proceedings. Now, Alek, the fifth member of their friend group and Livia’s cousin, is arriving as a newly decorated captain of Rave warriors. Livia bids farewell to her parents, Valen and Elise, and to her uncles, Tor and Sol (Alek’s fathers). She also has parting words for Stieg, her father’s captain. Before Valen leaves, he discreetly tells Livia that the nobles are maneuvering to marry their sons to her. Livia is troubled by this because she has never wanted a match with anyone who didn’t inspire passion in her, but her father assures her that he would never commit her to a marriage against her will. When her parents leave, Livia and the others plan their customary visit to the Chasm despite Livia’s internal trepidations.

Livia and the others travel by longboat to the beach and rocks nearest to the Chasm. As they drink, they banter over the noble’s plans for an arranged marriage. Later, Aleks finds Livia by the water, and she tells him of the foreboding feelings that she has had all day. Alek recommends that she be reckless at this festival and try something bold. Tipsy from drinking, Livia tells him of the one time she was bold: when she read stories to the imprisoned Erik Bloodsinger when they were both children. Alek tries to assuage Livia’s fears, reasoning that because the Chasm’s seal is made of Erik’s own blood, Erik cannot breach it. To prove this, Alek dives into the water, and Livia follows him. As she watches the cyclone of the Chasm, her hand, unbidden, rises to touch the current, and she feels a burning sensation in the scar left by Erik’s gold talisman so many years ago. As Livia and Alek hurry back to the festival, Livia reflects that she saw a golden city in the moment that her hand touched the Chasm. She believes that this is an omen.

Erik Bloodsinger and his pirate crew of the Ever ship travel the village of Rusa, inspiring fear and terror. They capture Rusa’s lord, Murdo, who stole Erik’s swallow-themed necklace in order to enact a spell to counter the rot in their lands. Erik makes a show of killing Murdo in front of the townspeople. He uses his own blood on Murdo. (Due to Erik’s blood magic, this blood would heal Murdo if Erik were to sing, but because Erik declines to do so, the blood kills Murdo instead.) As Erik reclaims the necklace, he is reminded of his hatred for Livia’s father, Valen, as well as his desire to possess Livia herself. Suddenly, he feels a jolt, and when he tastes the water, he detects the presence of his own blood, so he directs his ship toward the Chasm.

Erik and his crew sail to the edge of the Chasm and find it open. Emboldened, Erik directs the Ever ship through the Chasm, using his power as the Ever king to pass through the cyclonic waters without issue. When they emerge, he calls forth storm clouds to hide their arrival. As his desire for revenge surges, the crew sings out their Ever King crew’s famed sea shanty.

Erik waits for his scouts, Larsson and Celine, to return. Celine reports that the earth fae are having a festival and recommends that they enter the city as tradesmen. Disguised to hide their sea fae traits, Erik, Celine, Larsson, and other crew members make their way to the city. As they speak with other merchants, Erik sees Livia from afar, and the merchants he speaks with tell him that King Valen and Queen Elise have already left for their council meeting. The merchant also tells him that all the fae men must wait for the king to leave before approaching Livia because she is so beloved by Valen. Scheming, Erik plans to infiltrate the ballroom and take Livia, believing that she belongs to him.

Livia attends the great hall with her friend Mira as their other friends mill about. Privately, Livia believes that the men approaching her are doing so because of who her father is, not because they are interested in her as a person. She spies a man watching her in the ballroom and feels an instant and dangerous attraction to him. Though she doesn’t recognize him behind his mask, she accepts his dance request. Livia decides to be daring with him and insinuates that she could be his for the night. They speak as they dance, and Livia tells him of her window-painting hobby. She invites him to her room, propositioning him discreetly. When he accepts, she warns Mira of her intentions, then finds the stranger in the corridor, waiting for her.

Livia brings the stranger to her room, and as they engage in foreplay, the man discovers the scarred symbol of the gold talisman on her arm. She treats the topic dismissively. He asks her to play a game—two truths and a lie—the winner of which gets to do as they please with the other. However, when he mentions that his favorite story was that of the serpent and the songbird, Livia’s doubts arise. Then, when he calls her “Songbird” and lets his mask fall, she finally recognizes him as Erik Bloodsinger. He demands to have his mantle back—the mantle of kingship that Valen took from his father, Thorvald. Livia claims not to know where it is and struggles to get away, but he captures her and offers her an ultimatum: come with him quietly or he’ll have his crew slaughter everyone she loves. He then sets her room on fire and drags her out the window with him.

Erik drags Livia away from the castle, but as he is about to make his exit, Livia manages to wrangle herself away from him by kicking him in the leg. She flees and discovers that Erik’s crew is already attacking her people. When Livia sees no Rave warriors where the children are, she moves to check on her younger brother, Rorik. However, Erik catches up with her. Livia offers to go with Erik in order to keep Rorik safe. As Erik drags her away, Livia’s friends and family fail to rescue her, but Stieg confronts Erik and tries to stop him. When Stieg calls Erik by name, Livia is confused to realize that the two must have some shared history. Stieg warns Erik against starting a new war, but Erik dismisses him and throws himself off a cliff and into the sea, taking Livia with him.