Thomas travels to the Bodleian Library in Snowdonia to research the life and lost poem of poet Francis Blundy.

Prominent guests including novelist Mary Sheldrake and editor Harry Kitchener arrive at the Blundy estate for Vivien's birthday dinner.

Harry proposes a toast to Francis, who retrieves a vellum scroll and reads 'A Corona for Vivien' aloud to the assembled guests.

The dinner party receives Francis's poem with stunned silence before breaking into warm applause.

Thomas sails back to the South Downs campus, missing his former partner Rose Church and longing to collaborate with her again.

Thomas and Rose reunite romantically, declaring their love during a swim and committing to a shared future.

Thomas and Rose marry.

Thomas returns home from a trip to the Bodleian to discover Rose is having an affair with a student.

Thomas rediscovers a forgotten note from archivist Drummond identifying map coordinates hidden in Vivien's final journal.

Thomas and Rose travel by ship to the former Blundy estate and spend days excavating a buried container from the soil.

Thomas weeps when the unearthed container holds a prose manuscript rather than the lost poem.

Vivien's memoir reveals that Francis secretly entered Percy's house and staged his death as an accidental fall down the stairs.

Vivien reviews the poem after the Second Immortal Dinner and realizes it contains a depiction of Percy's murder.

Vivien burns the only existing copy of 'A Corona for Vivien' in her study.

Thomas publishes Vivien's memoir with a preface from Drummond and an introduction from Rose.

In the year 2119, scholar Thomas Metcalfe travels to a remote library to research the life of poet Francis Blundy and the lost poem that has defined his legacy. His obsession leads him to reconnect with his former partner Rose Church, and the two eventually marry, though Thomas's fixation on the past strains their relationship. After a period of academic and personal collapse, including the discovery of Rose's affair, Thomas follows a forgotten archivist's note to a buried container at the former Blundy estate. The discovery yields not the poem but a prose memoir written by Vivien Blundy herself. Vivien's memoir exposes Francis as a murderer who secretly documented his crime in the very poem Thomas has spent his life seeking. With the truth finally revealed, Vivien's long-ago decision to burn the poem is understood, and Thomas publishes her memoir as the definitive answer to his scholarly quest.

Thomas's quest for the lost poem, from the Bodleian to Vivien's shocking revelation.

Drummond draws Thomas's attention to a mysterious sequence of numbers recorded in Vivien's final journal.

Mary Sheldrake and her husband Graham arrive at the Barn fighting after Graham admitted to a recent affair.

Mary accidentally drops and smashes the ceramic salad bowl that Jane gave Francis and Vivien as a wedding gift.

The Gages arrive at the dinner in the middle of Francis's denialist speech about climate change.

Thomas and Rose co-teach a course on the Inundation that repeatedly fails to engage their students, until the two scholars become lovers.

Each dinner guest fails to give Francis's poem full attention, preoccupied by their own private concerns throughout the reading.

Harry writes Francis an effusive letter about the poem, providing the most detailed record of its content ever set down.

Harry publishes an article comparing Vivien's birthday dinner to the original Immortal Dinner of 1817, cementing its scholarly reputation.

Thomas befriends North American studies scholar Lars Corbel during a return visit to the Bodleian.

Vivien's memoir opens with her rescuing a young boy named Christopher from a suspicious stranger at a train station.

Vivien confesses to Percy that her daughter Diana died from neglect during a house party years earlier.

Harry ends his affair with Vivien, and she resolves to take revenge by pursuing his brother-in-law Francis Blundy.

During a getaway trip with Francis, Vivien observes his controlling and domineering personality for the first time.

Vivien and Jane conspire to sabotage Harry's archive, rendering it useless to future scholars.

Vivien buries Percy's violin and her memoir manuscript together in a sealed container near the former Blundy estate.

Thomas's painstaking reconstruction of the Second Immortal Dinner reveals the private dramas that unfolded among Vivien's guests, each too absorbed in personal concerns to give Francis's poem full attention. The dinner's later fame owes more to scholarly mythmaking than to any genuine appreciation felt in the room that night. Behind the scenes, Thomas's own romantic and academic life with Rose takes shape, beginning with their origins as co-teachers before deepening into a fraught partnership. Vivien's memoir then unfolds her secret life: her rescue of a child at a train station, her confession of her daughter Diana's death, and her calculated pursuit of Francis after Harry ended their affair. The memoir reveals how Vivien and Jane conspired to erase Harry's legacy from history, while Vivien took steps to ensure her own truth would survive. The container Thomas and Rose unearth becomes the unexpected vessel for everything Vivien chose to preserve.

The dinner's hidden dramas and the key moments behind Vivien's secret life.

Francis destroys all notes and drafts of his poem so that Vivien's copy is the only one in existence.

Vivien writes in her journal that the poem's narrative voice is deeply inconsistent with Francis's true character.

Vivien's journals reveal she placed Percy in a temporary care facility so she could spend time alone with Francis.

Thomas and Rose's seminar on the history of artificial intelligence ends with students walking out in collective protest.

Thomas discovers a note by Francis describing how the pursuit of a longed-for object inevitably disappoints when finally reached.

Thomas moves into a separate unit and immerses himself in increasingly quotidian research after discovering Rose's affair.

Thomas notices unexplained gaps in Percy's coroner's report, with Percy's death attributed to an accidental fall.

Thomas and Rose reconcile enough to plan and prepare a joint expedition to the former Blundy estate.

Rose guides Thomas's hand to her belly after they open the container, suggesting she is pregnant.

Vivien marries Percy while secretly maintaining an ongoing affair with Harry Kitchener.

Percy immediately forgets asking Vivien about having children, revealing how far his illness has already advanced.

Francis proposes murdering Percy, Vivien rejects the idea, but then secretly changes her mind without telling Francis.

Francis blackmails Vivien in Greece, threatening to frame her complaint emails as proof of murderous intent toward Percy.

Francis admits to killing Percy but insists the poem was written as a genuine act of love for Vivien.

Vivien resolves to destroy the only copy of the corona, seeing it as the only fitting act of vengeance for Percy's murder.

The novel's crucial turning points hinge on decisions made in secrecy and revelations that unravel long-held assumptions. Francis's choice to destroy all drafts of his poem sets the stage for the mystery Thomas will spend years pursuing, while Vivien's quiet journal entry marks the first crack in her understanding of their marriage. Thomas's own crises accumulate through a disastrous seminar walkout and the collapse of his marriage, forcing him to confront his escapist fixation on the past. In Vivien's memoir, the story's most consequential decisions surface: Francis's proposal to murder Percy, Vivien's silent change of heart, and his blackmail in Greece that traps her into marriage. The memoir's climax arrives when Francis admits his guilt while defending the poem, and Vivien chooses to destroy what could have been his greatest legacy. Together, these turning points trace both protagonists moving from passivity and obsession toward hard-won action and hope.

The decisions and discoveries that change everything for Thomas, Rose, and Vivien.