The unnamed narrator is a reflective, anxious woman who gives birth as a catastrophic flood submerges London. She has harbored a lifelong fear of the world ending but discovers profound purpose in the daily realities of motherhood. Her focus narrows to the immediate needs of her child, allowing her to block out the overwhelming scale of the environmental disaster.

The infant son of the Nameless Narrator and R. His developmental milestones, from his first smiles to crawling, provide a timeline for the story and a sense of progression amidst chaos. He possesses an innate comfort with water and travel, offering his mother a vital anchor to the present.

The narrator's partner, a man with a strong affinity for wilderness survival. He struggles profoundly with the trauma of societal collapse and the burden of protecting a new family. He frequently experiences panic in crowds and responds to the ongoing disaster by seeking isolation or physical distance from the chaos.

A gentle-natured mother who forms an immediate, intense bond with the narrator. Navigating the disaster alone with her infant, she provides practical solidarity and emotional grounding. She favors communal living and shared responsibilities, offering a stark contrast to the isolation the narrator experiences elsewhere.

R's father, who provides initial refuge for the family. He remains fixated on the ongoing disaster, maintaining a constant background noise of news broadcasts on the television that unnerves his daughter-in-law.

R's mother, characterized by her nervous, constant chatter. She attempts to maintain a sense of domestic normalcy by establishing a routine of difficult, hazardous supply runs to gather scarce groceries for her newly expanded household.

A friend of R's who is enlisted to support the narrator until R can return from the mountains. He is visibly uncomfortable around a woman in labor and prioritizes drinking beer and watching sports over offering practical assistance.

An uninvited guest who accompanies S during the narrator's labor. He treats the situation with casual detachment, focusing on television and drinks before eventually helping to call an ambulance when complications arise.

A fellow mother navigating the crisis alone. She provides early comfort to the narrator, validating her maternal anxieties and offering a brief glimpse of solidarity before leaving the camp to seek a safer location.

O's infant child. Unlike Z, C struggles with the disruptions of their journey, particularly during a treacherous sea voyage where the child is noticeably frightened and miserable.

An old friend of O's who maintains a safe haven on a high-cliffed island untouched by the floodwaters. He advocates for a humanitarian approach to the crisis, hoping to eventually rescue more refugees, and establishes a stable, communal household.

H's wife, a gentle woman who helps integrate the narrator and O into their family's routine. She works alongside the others to cultivate a garden and divide household chores, creating an environment of domestic tranquility.

One of H and F's older children. To the narrator, the older children seem entirely foreign compared to her fragile newborn, representing a stage of development that feels impossible to imagine reaching in such a broken world.

The second of H and F's older children. The child learns basic infant care from the narrator and O, contributing to the blended family's cooperative survival strategy.

A young man who assists the narrator and O during their journey north. Though his intentions are ultimately non-threatening, his presence reminds the women of their physical vulnerability in a lawless landscape.

A young man who helps guide the mothers to the coast. He declines their invitation to board the boat, leaving the women to navigate the final sea crossing alone.