Thomas is a literary scholar at the University of the South Downs in 2119, a future defined by the ecological catastrophe known as the Inundation. He spearheads the "90-30" program, specializing in English literature from 1990 to 2030. Deeply dissatisfied with his present era's focus on mere survival, he idolizes the pre-crisis world and obsesses over reconstructing the sequence of events surrounding Francis Blundy's legendary lost poem. His fixation on the past severely strains his real-world interactions.

Vivien is a 21st-century woman whose detailed personal journals provide future scholars with their only window into the fabled Second Immortal Dinner. She is the wife of acclaimed poet Francis Blundy, for whom she manages the household and sacrifices her own academic ambitions. Before marrying Francis, she was married to Percy Green, a violin maker whose battle with early-onset Alzheimer's disease forced her to abandon her teaching career to become his caretaker.

Francis is a highly celebrated poet whose life bridges the 20th and 21st centuries. He enjoys massive fame in future academic circles for writing "A Corona for Vivien," a poem he read exclusively to a small group of friends in 2014 before allegedly destroying all drafts. Despite his romantic literary reputation, historical accounts reveal him to be a stubborn, self-centered figure who loudly denies the existence of climate change and demands complete domestic subservience from his wife.

Rose is a literature scholar who works alongside Thomas Metcalfe. She studies the inadequacy of realist fiction in the 2020s and maintains a highly pragmatic view of history. Unlike Thomas, she refuses to romanticize the pre-catastrophe world, recognizing that historical study should inform the present rather than serve as an escape. She frequently challenges Thomas's obsession with recovering lost artifacts.

Percy is a gentle, musically gifted man who works as a reputable violin maker and occasionally plays the banjo at a jazz pub. He has no interest in literature, which creates a mild cultural divide between him and Vivien. His life changes drastically when he begins experiencing memory lapses in his early fifties, leading to an early-onset Alzheimer's diagnosis that transforms him from an independent craftsman into a highly dependent patient.

Harry is a poet, university professor, and editor who champions his brother-in-law Francis's work. Despite his own literary career, he operates largely in Francis's shadow. He originally plans to write Francis's biography and plays a central role in cementing the mythos of the Second Immortal Dinner by comparing it to historical literary gatherings in the press.

Jane is Francis's sister and Harry's wife. She resents her brother for easily discarding the strict religious upbringing that she still struggles with. At the dinner party, her focus on a broken wedding gift distracts her entirely from Francis's poetry reading, highlighting the emotional disconnect between the siblings.

Mary is a highly popular and successful 21st-century novelist. She attends the fabled dinner party, bringing prestige to the guest list. However, her experience of the night is dominated by severe marital conflict and sudden feelings of artistic inadequacy when she compares her commercial prose to Francis's complex poetry.

Graham is Mary Sheldrake's husband. He spends the entirety of the Second Immortal Dinner preoccupied by recent discoveries about his wife's affairs and his own past transgressions, entirely missing the content of the famous poem being read.

Harriet is a journalist and profile writer who originally entered the Blundys' social circle after writing a piece about Francis for Vanity Fair. Following Francis's death, she becomes one of the key voices speaking to the press about the lost poem, though her memories of the night are heavily colored by her own concerns as a new mother.

Chris is a former college dropout working as a builder. He feels out of place among the literary elite at the Blundy estate and frequently clashes with Francis over matters of vocabulary and intellectual pretension.

Tony is a literary botanist invited to the Second Immortal Dinner. He possesses a deep knowledge of flora and fauna, which causes him to view Francis's sudden poetic interest in nature with high skepticism and quiet contempt.

John is a veterinarian who attends the dinner party. He is entirely disconnected from the literary gravity of the evening, spending the famous poetry reading worrying about a snake he recently treated for a spinal injury.

Rachel is Vivien's sister. She frequently steps in to help manage Percy's care, allowing Vivien brief periods of freedom from her difficult domestic responsibilities. She acts as Vivien's practical sounding board during times of crisis.

Peter is Rachel's son and Vivien's nephew. Before Percy's illness becomes too severe, Peter acts as his apprentice, learning the delicate craft of violin construction. This shared passion creates a warm bond between the two that persists even as Percy's memory fades.

Donald is an archivist working with the surviving physical texts at the Bodleian Library. He attempts to collaborate with Thomas on deciphering cryptic clues left in Vivien Blundy's journals, though Thomas initially rebuffs his enthusiastic help.

Lars is a scholar specializing in North American studies in 2119. Unlike Thomas, Lars is highly engaged with the political activism of his era and views historical repetition with optimism rather than despair. He quickly identifies Thomas's total detachment from contemporary reality.

Kevin is a university student in 2119 who acts as the spokesperson for his peers. He openly challenges Thomas and Rose's curriculum, arguing that studying the past is useless and expressing his generation's exhaustion with historical nostalgia.