Nora Seed
Nora Seed is the main character of the novel. She is a woman in her thirties, who leads a life she finds lonely and disappointing. Once a gifted swimmer and musician, she currently works in a music shop and gives piano lessons. She has a difficult relationship with her brother and feels generally detached from the world around her. She spends a great deal of her time reflecting on her regrets, like not pursuing a career with her band the Labyrinthes and calling off her engagement to her ex-boyfriend. After a particularly bad day, she decides that she no longer wants to keep living. She is portrayed as a thoughtful and sympathetic person, often thinking about the emotions of the people around her. After her overdose, the novel follows her imaginative journey through the various lives she didn't lead.
Mrs. Elm
Mrs. Elm is the librarian from Nora's elementary school days. The novel opens with her playing chess with Nora and talking about the possibilities of life. She later reappears as a younger version of herself in the Midnight Library, where she assists Nora in traveling to her various unlived lives.
Nora’s Father
Nora's father dies when she is fairly young. But in her life as a competitive swimmer, he is alive. He is depicted as pushing her to work hard and pressuring her to try to compete in the Olympics.
Dan Lord
Dan is Nora's ex-fiancé. In her real life, she often ruminates about their breakup. However, in one of her parallel lives, she learns that he is unhappy with her and cheats on her. He is portrayed as being more interested in the idea of being married to her than the reality of their relationship.
Ash
Ash is a surgeon and Nora's neighbor who informs her that her cat has died. He also purchases a Simon and Garfunkel guitar songbook from her at the music store. He asks her on a date once and she wonders if there might be something between them romantically. In a parallel life, they are happily married.
Izzy
Izzy is Nora's best friend. She is described as loving and warm. Nora feels sad that they have drifted apart over the years.
Joe
Joe is Nora's brother. They were in a band together and their relationship was fractured when Nora decided to not pursue a record deal or tour with the band. Joe is gay and struggles with his father's disapproval of his sexual orientation.
Hugo Lefèvre
Like Nora, Hugo is a fellow traveler through his alternative lives. He is described as being somewhat aloof and cold as a result of his continual journey through parallel timelines.
Ryan Bailey
Ryan Bailey is a fictional movie star. Nora has a crush on him and in her alternative life as a rockstar, she dates and breaks up with him. When Nora meets him, she finds him to be less interesting and intelligent than she envisioned.
Molly
Molly is Nora's daughter. She is described as a sweet and happy child.