The Siren

Roughly 80 years before the story's present day, 19-year-old Kahlen is traveling by ship with her wealthy American family when a violent storm strikes. An intoxicating song draws passengers onto the deck, where they behave erratically. Kahlen watches her parents smile as they tip themselves over the railing hand in hand before the song overtakes her, too, and she plunges into the water. As she drowns, a voice asks what she would give to stay alive. She answers, "Anything." Pulled from the sea, Kahlen finds herself on the water's surface facing three supernaturally beautiful girls, Marilyn, Aisling, and Nombeko, who explain they are sirens, servants to a sentient Ocean who feeds on human lives. In exchange for 100 years of service, a siren will not age or be hurt, and when her time ends, she regains her voice, freedom, and life. Kahlen chooses to stay and is pulled underwater, where something cold is forced into her veins, transforming her.

Eighty years later, Kahlen lives in a Miami beach house with sister sirens Elizabeth and Miaka. She is haunted by nightmares of the people she has helped kill and keeps scrapbooks documenting shipwreck victims to cope with guilt. The sirens' rules are absolute: stay silent around humans, since their voices are lethal; sing without hesitation when the Ocean calls; and never expose their secret. Cautionary tales reinforce these rules: Disobedient sirens have been drowned, driven to despair, or worse.

At the university library, Kahlen meets Akinli, a blond-haired student who strikes up a conversation about the cake books she is reading. Unlike others drawn to sirens' supernatural beauty, he speaks to her rather than staring. When Kahlen signs her name instead of speaking, Akinli adapts without hesitation, offering his hand so she can write on his palm. Over several encounters they grow close. He invites her to bake a cake in his dorm kitchen. They bake a two-tiered cake together, and when Akinli shares it with his entire floor, Kahlen briefly experiences the normalcy of college life. Joy turns to dread, however, as she realizes she will never age, might disappear without warning, and will forget Akinli when her sentence ends. She silently slips away.

Kahlen uproots her sisters to Pawleys Island, South Carolina, where the Ocean explains that Kahlen's nature craves deep love rather than casual connections.

The Ocean later summons the sirens to the Arabian Sea, where they find Padma, a beaten 16-year-old with cinder blocks tied to her limbs, thrown into the sea by her father because a daughter was too expensive. Kahlen explains siren life, and Padma eagerly accepts, seeing the sisterhood as liberation. Aisling, nearing the end of her century of service, confides that she secretly watched her daughter Tova's descendants for decades and advises Kahlen to watch over Akinli from afar. On Christmas Eve, the sisters witness Aisling's painful transformation back to human and leave her at a Swedish boarding school where her great-granddaughter teaches, knowing Aisling will remember nothing of her siren years.

When the Ocean next calls them to sing, the ship is a cruise liner hosting a wedding. Kahlen sees the bride sliding beneath the waves and stops singing, momentarily breaking the spell. Elizabeth tackles Kahlen and forces her to resume. Devastated, Kahlen flees.

An unconscious pull draws Kahlen to Port Clyde, Maine, where Akinli discovers her by the lighthouse. He has dropped out of school after his parents' death and now lives with his cousin Ben and Ben's wife Julie. They let Kahlen stay. Over the following days, she and Akinli share their grief, explore nearby Rockland, and hold hands for the first time. Akinli notices Kahlen's invulnerability and, rather than being afraid, offers her his parents' empty house and promises to protect her.

Kahlen agrees to stay. Akinli kisses her on the beach, and overcome with emotion, Kahlen whispers "Wow." Her siren voice takes effect: Akinli's eyes glaze over, and he walks mindlessly into the Ocean. Kahlen chases him beneath the surface, where the Ocean seizes him, declaring he is Hers. Kahlen begs for his life, and after a tense standoff, the Ocean releases Her grip. Kahlen drags Akinli to shore, confirms his heartbeat, and whispers that she loves him before forcing herself back into the water.

The Ocean adds 50 years to Kahlen's service and warns She will end Akinli's life if Kahlen disobeys again. In New York, where her sisters find her, Kahlen isolates herself, throwing her scrapbooks, keepsakes, and her mother's rusted bobby pin into the water. Kahlen vows never to say Akinli's name again if the Ocean protects him for life, and the Ocean agrees.

Despite the command, Kahlen unconsciously draws Akinli's face. Elizabeth and Miaka piece together clues and begin secretly visiting Port Clyde to monitor him. Meanwhile, Padma's memories of abuse persist, and Kahlen secretly orchestrates a trip to India where her sisters kill Padma's abusive parents. During the next singing, Kahlen's body begins to fail, as she cannot breathe underwater and her voice gives out mid-song. When Padma accidentally reveals the trip, the Ocean threatens death if the sirens disobey again.

Kahlen's health deteriorates with fevers, weight loss, and exhaustion, all impossible for a siren. Her sisters reveal their visits to Port Clyde and show Kahlen photographs of Akinli: gaunt, in a wheelchair, suffering from an illness that mirrors her symptoms. Kahlen reads Franz Kafka's short story "The Silence of the Sirens," which proposes that a siren's silence is more deadly than her song. The Ocean reveals that siren voices are poison, and Elizabeth theorizes that Kahlen's silence is slowly killing Akinli, though this does not explain why Kahlen is also dying.

Kahlen's sisters carry her to the Ocean, who floods through Kahlen's memories and feels the depth of her love. The Ocean finally confesses: Kahlen and Akinli's souls are bonded, and because her siren voice has poisoned him, their fates are linked. The only cure is for Kahlen to be changed back to human, restoring her voice and healing them both. The Ocean resists, devastated at losing Her most beloved siren, and confesses Her loneliness. Miaka, Elizabeth, and Padma volunteer to extend their own service to compensate for Kahlen's remaining time. Bound by Her promise to protect Akinli, the Ocean agrees.

The transformation strips Kahlen of her siren nature and her memories. She awakens being carried by three girls she does not recognize, who set her on the porch of Ben and Julie's house. Each offers a silent farewell before disappearing. Ben and Julie bring Kahlen upstairs to Akinli, who is bedridden and skeletal with tubes in his nose and veins. His eyes fill with tears when he sees her. Kahlen does not recognize his face but tells him she knows his voice as if it were her own. He pushes himself upright for the first time in months, and they lean into each other. On her wrists, someone has written "You are Kahlen" and "He is Akinli."

Day by day, the illness retreats, and doctors call it a miracle. Akinli retells their story, and Kahlen concludes their meeting was fated. Julie finds a bag on the porch containing cash and a bottle of perpetually cold, dark blue water with tiny shells that never settle. Kahlen sleeps with the bottle, sensing that treasuring it means treasuring herself. She loves her recovering body, her soul mate, and her adopted family.