Hannah distracts herself in her apartment by folding paper into tiny squares. In the middle of the night, her mother and cousin Rory show up and demand that Hannah stitch Rory’s face. He claims that three privileged-looking men beat him up, and Hannah suspects that they must be from the nearby Hawthorne Island, owned by a billionaire with one son: Tobias. Hannah treats Rory, but her mother is cold toward her, and Hannah is cold in return. When they leave, Hannah suspects that they’ll be back.

Hannah goes out to an old lighthouse every two weeks. She loves the isolation and brings groceries to Jackson, the lighthouse keeper. Jackson is even surlier than Hannah, which is why she understands him. He tells her that a storm is coming, and later, Hannah sees lightning near the mansion on Hawthorne Island. Suddenly, an explosion goes off, setting the whole place aflame.

Jackson appears at Hannah’s door for the first time ever, clearly in distress. He asks Hannah to come with him back to his shack near the lighthouse, where the only survivor of the explosion awaits treatment. Jackson found him in the water and saved him; he is certain no one else survived. He insists that Hannah not call the police because he believes the survivor is responsible for the fire and knows that Hannah’s family will come after him. When Hannah hears that her sister was at the mansion when it exploded, everything changes.

Hannah knows she has an obligation to help but wishes that she didn’t. She feels angry and believes that Toby is responsible for her sister’s death. She finds Toby on the floor of the shack, covered in burns and blood. Jackson provides a bag of medical supplies, and Hannah does what she can to treat Toby. She notices that his face is unharmed and wonders how that is possible.

Hannah leaves Jackson with some brief instructions and no intention of returning. She sets her mind on reaching the island, whether her sister is alive or dead. Before going out there, Hannah stops at her family home, where she finds her father alone. He hits her and blames her for Kaylie’s death but then hugs her and tells her to leave. Hannah manages to convince one of the men at the bar to take her out to the island, but the Coast Guard forces them back and declares that there were no survivors.

Hannah tries to go in for a shift at the hospital but is told to go home and grieve instead. She decides to go to the lighthouse to find out if Toby is alive. She finds him lying on the floor, alive but in pain. Hannah relishes his suffering and tells herself that he deserves it for what happened to Kaylie. She treats his wounds, but as she does so, she thinks about how much she hates him. Toby wakes up briefly and asks Hannah to let him die, but Hannah would rather that he live with what he did.

Hannah stays for three days, and when Toby finally wakes up, he doesn’t remember who he is or what happened. Jackson tells him his name is “Harry,” and Toby can only recall vague personality traits, like being a troublemaker. He asks Hannah her name and points out that it’s a palindrome. He also seems to enjoy the pain relievers a little too much.

On day four, it becomes clear that Toby may live. His wounds remain uninfected, but Hannah suspects neurological damage that may affect his body as well. She offers to go out for more supplies, adding that she plans to stay away from Rockaway Watch.

Hannah continues treating Toby’s burns. When Toby looks at Hannah with pity, Hannah starts to feel like a patient herself. Toby is in severe pain but manages to point out Hannah’s habit of building castles with sugar packets. He asks if she believes in fairy tales, and she answers that she believes in villains. She wonders, though, which of them will be the villain in this story.

Hannah goes to get more supplies. When she comes back, she finds Toby (now referred to as Harry) sitting up and drinking whiskey. Jackson says that they ran out of medication. Seeing this irritates Hannah, and she leaves.

Hannah goes back to her apartment and finds a note from her mother asking her to come to the house at 8:00 pm for Kaylie’s wake. Hannah wears a gray shirt and jeans and, like her mother, hides her grief from the family. Hearing her mother speak of Kaylie’s death makes it feel more real. Hannah goes down to the den, where she finds several of her cousins. There, Hannah discovers a newspaper that blames Kaylie for the fire. Everyone toasts Kaylie, and Hannah finds a way to slip out. She thinks about how easy it would be to leave town now that Kaylie is gone but finds herself returning to the shack and to Toby instead.

Hannah returns to find Jackson inebriated and Toby asleep. She thinks about how Kaylie is being blamed for the explosion and how much she hates Toby for it. When Toby starts writhing in his sleep, Hannah attempts to calm him and wake him up. Moments later, Toby is reciting palindromes, and Hannah knows that he’s taunting her.