Pete is a young teenager living with his family in a house on Sycamore Street. After his father sustains severe injuries at a job fair, Pete finds a buried trunk containing cash and handwritten notebooks in the woods behind his home. Seeking to ease the intense marital friction between his parents, he begins secretly mailing the cash to his father. He develops a deep passion for reading, which ultimately leads him to investigate the origins of the notebooks.

Morris is an intensely devoted fan of the fictional character Jimmy Gold. He harbors immense anger toward the character's creator for forcing Gold to settle into a domestic lifestyle. Driven by a desire to read unpublished material, he organizes a home invasion to steal private notebooks filled with continuations of the story. A subsequent arrest for an unrelated barroom assault results in a life sentence, separating him from the stolen literature for decades.

Bill is a sixty-six-year-old retired police detective who operates a private firm named Finders Keepers. Following a doctor's warning about his heart health, he maintains a strict diet while continuing his investigative work. He carries emotional weight from the tragic death of a woman he loved during a previous case involving the Mercedes Killer, causing him to take a highly protective stance toward new clients.

Andy works in the rare book trade and operates his own store. In 1978, he refuses to help fence stolen materials, pragmatically advising that the goods be buried instead. Years later, he encounters a young person attempting to appraise handwritten literary pages, bringing his past knowledge back into play. He maintains a shrewd, self-serving approach to his business dealings.

Holly is a partner at the Finders Keepers detective agency. She exhibits a highly analytical mind and consistently notices subtle details that elude others. She manages her obsessive-compulsive routines through strict habits and relies on her friendship with Bill to gradually increase her comfort with social interactions.

Tina is Pete's younger sister who hopes to attend a local private school called Chapel Ridge. She closely observes her brother's changing behavior and correctly deduces his connection to anonymous envelopes of cash appearing at their house. Fearing for his physical and mental safety, she proactively seeks professional assistance.

Tom is a former realtor who loses his career during an economic downturn. He suffers devastating physical trauma when a vehicle plows into a crowd of unemployed workers, leaving him temporarily disabled and dependent on pain medication. His sudden inability to provide for his family creates extreme tension within his household.

Linda works as a librarian following the closure of the elementary school where she previously taught. She carries the immense stress of functioning as the sole provider for her family after her husband's injury, resulting in frequent domestic arguments over bills and housing.

John is an elderly, historically significant author famous for creating the beloved character Jimmy Gold. Having ceased public publishing years ago, he continues to write prolifically for his own enjoyment in private notebooks. He views his literary creations as his exclusive property, fiercely defending his right to end stories on his own terms.

Jerome is an associate of the Finders Keepers detective agency and Barbara's older brother. He provides reliable physical assistance and surveillance support when Bill and Holly begin investigating Pete's unusual activities.

Brady is the notorious Mercedes Killer responsible for injuring Tom Saubers and murdering numerous bystanders years prior. He currently resides in a medical facility in a semi-catatonic state following severe head trauma, though his former investigator suspects he retains more awareness than medical professionals believe.

Mr. Ricker is a high school educator who recognizes Pete's exceptional passion for writing research papers. He offers Pete casual advice regarding local rare book dealers when the student claims to possess old texts to sell.

Curtis acts as one of Morris's accomplices during the 1978 home invasion. He participates solely to secure the cash located in the author's safe and lacks any intellectual interest in the stolen writing materials.

Freddy serves as the third member of the group executing the break-in at Rothstein's home. He questions Morris's extreme actions and violence during the crime, illustrating a fundamental divide between common thieves and an obsessed fanatic.

Ellis operates as the parole officer assigned to monitor Morris after his release from a lengthy prison sentence. He pays close attention to his parolee's physical appearance and routinely administers drug tests to ensure compliance.

Barbara is Tina's supportive friend and Jerome's younger sister. She acts as a comforting presence when Tina decides to ask adult professionals for help regarding Pete's strange behavior.

Anita is Morris's mother and a Pulitzer Prize-nominated writer. Her literary success created a deep sense of inadequacy in her son, leading to a massive argument regarding fiction that precipitated his downward spiral.

Cora Ann works at a bar and is the victim of Morris's brutal assault in 1978. She attends his parole hearings for decades to ensure he remains incarcerated, before eventually penning a letter to the board due to a terminal illness.

Janey is Bill's former romantic interest who died tragically in an explosion during a previous investigation. Bill continues to mourn her loss heavily and alters his dietary choices to honor her memory.

Todd is a friend of Tom Saubers who waits in line with him during a heavily crowded employment event seeking work.

Charlie is a former inmate who served time alongside Morris. He currently works at a motorcycle shop and provides Morris with a vehicle as a return favor for past assistance with legal correspondence.