Mukesh is a 70-something retired railroad ticket taker and widower living in West London. Since the passing of his wife Naina, he fills his days with strict routines, attending the neighborhood mandir, and watching David Attenborough nature documentaries. He feels a growing distance from his three busy daughters and struggles to connect with his book-loving granddaughter Priya. Finding an overdue library book among his late wife's possessions prompts him to visit the local library and try reading fiction for the first time.

Aleisha is a 17-year-old student taking a summer job at the library before heading to university to study law. She dislikes reading and initially finds her days at the desk incredibly boring. At home, she carries the heavy responsibility of caring for her mother, leaving her little time to enjoy a typical teenage social life. She acts defensively with strangers to protect her limited emotional energy but begins to open up when she decides to read titles from a mysterious list left in a returned book.

Aidan is Aleisha’s older brother who works long hours at a biscuit factory. He previously planned to open his own mechanic business but shelved his ambitions to support his mother and sister after his father left. He acts as the primary financial provider for his household and repeatedly encourages Aleisha to go out and experience her youth.

Naina is Mukesh's late wife, who passed away from cancer two years prior to the story's main events. During her life, she was a passionate reader who frequently brought stacks of books home from the Harrow Road Library. She remained deeply integrated into her local community and shared a special bond over literature with her granddaughter Priya.

Leilah is the mother of Aleisha and Aidan. Following the sudden departure of her husband seven years ago, she developed severe depression and rarely leaves the house. She relies entirely on her children for financial support and daily care, finding brief moments of comfort when Aleisha reads stories to her in bed.

Priya is Mukesh and Naina’s young granddaughter. She is an avid reader who frequently buries her nose in a novel rather than engaging in conversation with her family. She misses the literary connection she used to share with her grandmother, which creates a noticeable distance between her and her non-reading grandfather.

Zac is a friendly young man whom Aleisha repeatedly bumps into around Wembley. He studies law, frequently reads on public transit, and wears a distinctive beanie. He attempts to strike up conversations with Aleisha, offering her a glimpse of a normal teenage social life outside her demanding family duties.

Nilakshi is a widow from the neighborhood and a former friend of Naina Patel. She is active in the local mandir and begins spending time with Mukesh, cooking him dinner and keeping him company on charity walks.

Rohini is one of Mukesh and Naina’s three adult daughters and the mother of Priya. She worries about her father's isolation and pushes him to participate in community events, like a local charity walk, to break him out of his solitary routine.

Deepali is one of Mukesh’s adult daughters. She checks in on her father's wellbeing but is quick to express disapproval when she suspects he might be moving on too quickly or behaving improperly regarding her mother's memory.

Vritti is the third of Mukesh’s adult daughters. She frequently hosts family lunches and stays busy with her own life while trying to monitor her father's grieving process from a distance.

Indira is one of Naina Patel’s closest friends. She attends weekly prayer sessions and feels a deep sense of loneliness as her social circle shifts and friends move away, eventually seeking solace at the Harrow Road Library.

Dean is Aleisha and Aidan’s estranged father. He abandoned his family seven years ago to start a new life with another partner. His departure caused deep psychological fractures in the household, forcing his children to assume adult responsibilities.

Chris is a local resident who turns to the Harrow Road Library to cope with the aftermath of his separation from his girlfriend. Aleisha silently dubs him "Crime Thriller Guy" due to his reading preferences.

Izzy is a busy London resident with a unique hobby of collecting discarded shopping and to-do lists to imagine the lives of strangers. She feels adrift in the large city and uses the library to find a sense of belonging.

Joseph is a young student who frequently faces bullying at school. He utilizes the quiet sanctuary of the library as a safe haven to read and avoid his tormentors.