The novel unfolds across three interwoven timelines on Winthrop Island, a fictional enclave in Long Island Sound where wealthy summer families, known as "the Families," coexist uneasily with a working-class, mostly Portuguese community of fishermen and laborers.
In May 1969, Miranda Schuyler, now famous as the actress Miranda Thomas, returns to Winthrop Island after 18 years, hiding a bruised face behind dark sunglasses. At the general store, the elderly proprietress Mrs. Medeiro recognizes Miranda and drives her to Greyfriars, the once-grand Fisher estate now converted into an artists' colony. Miranda learns that Joseph Vargas, Mrs. Medeiro's grandson, has escaped from prison, where he was serving a sentence for murdering Miranda's stepfather, Hugh Fisher. Miranda's stepsister, Isobel Fisher, greets her at the door.
The narrative shifts to 1930, introducing Bianca Medeiro, a 17-year-old orphan raised by her aunt and uncle on the Island. Bianca is infatuated with Hugh Fisher, a 22-year-old from a newly wealthy family whose estate overlooks the Fleet Rock lighthouse. When Hugh visits the store seeking bootleg liquor, he notices Bianca for the first time and kisses her hand. Bianca's cousin Francisca, who had a secret affair with Hugh the previous summer, is now engaged to Pascoal Vargas, an older lobsterman appointed to keep the lighthouse.
The central storyline begins in June 1951. Miranda is 18, and her widowed mother is marrying Hugh Fisher. On the wedding morning, Miranda watches Joseph Vargas, a young lobsterman, dive into the sea to rescue a fisherman who has fallen from his boat. Over coffee afterward, Joseph quotes Shakespeare's
The Tempest, the play from which Miranda's late father, an art teacher killed in World War II, chose her name.
Isobel Fisher, Miranda's new stepsister, is a restless 20-year-old engaged to Clayton Monk, a lawyer from a wealthy Boston family. Isobel warns Miranda away from Joseph, declaring possessively that he is hers. After the wedding, the newlyweds depart for a European honeymoon. That evening, Isobel takes Miranda across the channel to Fleet Rock, where Miranda recites Henry V's battle speech, deeply moving Joseph. As he rows them home, Miranda realizes she is in love with him.
Over the following weeks, Miranda becomes an unwilling go-between, delivering notes between Isobel and Joseph, tormented by her belief they are lovers. The Countess, Isobel's mother and Hugh's formidable ex-wife, arrives from France to chaperone Isobel. Clay Monk confides to Miranda that he fears Joseph is in love with Isobel. At a party, Isobel publicly breaks off her engagement to Clay.
The 1930 timeline advances. Hugh Fisher's abusive father dies on the Fourth of July. Grieving and drunk, Hugh seduces Bianca by the pool, taking her virginity. Bianca interprets their union as a sacred marriage before God. Weeks later, Hugh reveals his wedding to Abigail Dumont will proceed as planned, devastating Bianca. Bianca's cousin Laura reveals that Francisca also slept with Hugh and had a secret abortion. Consumed by rage, Bianca deliberately seduces Pascoal over three afternoons, ensuring she can claim her coming pregnancy is his.
In August 1951, Joseph invites Miranda lobstering. During a swim, he kisses her and confesses he has loved her all summer, insisting his bond with Isobel is only friendship. He urges Miranda to pursue acting. They return to find Hugh and Miranda's mother home early; at dinner, Miranda's mother announces she is pregnant.
That night, Miranda meets Joseph at Fleet Rock, where he reveals a devastating secret: Hugh Fisher is his biological father. Joseph's mother had an affair with Hugh before his marriage, and Mrs. Vargas married Pascoal to give the baby a name. Francisca, who was supposed to marry Pascoal, drowned the night Joseph was born. Isobel knows the truth: She and Joseph are half-siblings, which explains their closeness.
In the lighthouse, Miranda mentions her mother's pregnancy. Mrs. Vargas, overhearing, drops a tray of porcelain in shock. Miranda's memory of the night is fragmentary: Joseph appears with blood on his shirt, announcing Hugh Fisher is dead. Joseph pleads guilty to second-degree murder and goes to prison.
The 1969 timeline resumes as Miranda renovates Greyfriars with her own money and meets her 17-year-old half-brother, Hugh Fisher Jr., for the first time. At the Winthrop Island Club, the Families' social hub, Clay Monk welcomes them. Miranda privately discloses the truth about her husband, Carroll Goring, a famous and controlling film director. Carroll attacked her in a jealous rage and crashed their car while drunk, ending her six-month pregnancy. Mysterious roses keep appearing at Greyfriars, and Miranda suspects Joseph is nearby. One night, deeply drunk and despairing, Miranda wades into the ocean, losing the will to step back. Unseen arms pull her to safety; she wakes the next morning with fresh roses on her nightstand.
Two U.S. Marshals spend the summer hunting Joseph, but the Islanders refuse to cooperate. Miranda organizes a performance of the first act of
The Tempest for a beach party hosted by Tom Donnelly, a respected local builder. Carroll tracks Miranda to the Island; when she refuses reconciliation, Hugh Jr. throws him off the property.
Miranda stages the play at sunset. Brigitte, an elderly Austrian watercolorist among the artist residents, plays Caliban, lifting her arm to expose a concentration camp tattoo. Isobel's performance as the character Miranda comes unexpectedly alive opposite Hugh's Ferdinand. Afterward, Miranda slips away to meet Joseph, who has been hiding in Fleet Rock's lamp room while caring for his mother, who is dying of cancer. They make love for the first time. Miranda begs him to sail to freedom on a yacht she bought for Hugh Jr., but Joseph refuses.
When Mrs. Vargas needs a priest, Joseph leaves to fetch one. The delirious woman mistakes Miranda for a priest and confesses: She, not Joseph, killed Hugh Fisher. She overheard Miranda telling Joseph about the pregnancy and understood Hugh had broken his vow to love only her. When Hugh came to the lighthouse, she was waiting with a kitchen knife. Unable to confess to her son, she let Joseph believe the death was accidental, and he pleaded guilty to protect her.
Isobel arrives with the priest and reveals her own guilt: She saw Miranda and Joseph together in 1951 and woke her father, sending him to the lighthouse. Isobel turns off the lighthouse while Donnelly sets the old clubhouse ablaze as a diversion. On the beach, the marshals seize Joseph. Clay Monk fires from the darkness, striking one marshal. Joseph dives in to rescue the wounded man rather than fleeing. In the confusion, he slips beneath the water and vanishes.
Back at Greyfriars, the marshals search the house. Mrs. Vargas dies during the night. Joseph, who has swum to shore and hidden in a compartment above the boathouse ceiling, drops into a dinghy that Miranda and Isobel carry to the water. Isobel dumps the boat, sending Joseph unseen beneath the dock. By morning, the yacht has vanished from its mooring.
An afterword set in 1931 shows Hugh visiting the pregnant Bianca at the lighthouse. He swears she may kill him if he ever loves another woman first. Bianca, ostracized and married to Pascoal, invites him inside, accepting their destructive bond.
A final afterword in spring 1970 finds Miranda at a thriving Greyfriars. With Clay's help, she has secured a presidential pardon for Joseph, publicized widely so he will learn he is free. Postcards from Joseph, bearing no message, arrived through the winter and stopped after the pardon. Miranda stands on the dock, pregnant, reciting Shakespeare to the moonlit water. A sail appears around the lighthouse and beats its way up the channel toward her.