Leo is an eleven-year-old orphan who makes a living selling newspapers after his father's recent death from a fever. He lives independently in a boarding house and relies on his family's stories of survival to find courage in his daily routine. He carries a gold nugget that connects him to his past and gives him strength when he feels lonely or afraid.

Morris is a younger boy living in the same boarding house as Leo. He spends a significant amount of his time reading at the local library and eagerly shares the facts he learns. Despite dealing with a neglectful uncle, he remains desperate for connection and persistently tries to befriend Leo.

Fletch is a notorious neighborhood thief who recently escaped from a work farm. He possesses a raspy voice resulting from a stray dog attack he suffered at age five. He uses intimidation and violence to control the local streets and frequently targets smaller children for their valuables.

Wilkie is an imposing youth weighing nearly three hundred pounds with a powerful physical presence. He acts as Fletch's enforcer and sidekick, backing up the smaller boy's criminal plans. He harbors hidden athletic talent, having once been scouted by a Seattle high school football coach, but chooses to remain on the streets.

Grandpop is Leo's deceased grandfather who traveled to California from New Hampshire during the gold rush at age sixteen. Though he died before Leo was born, his legacy shapes Leo's understanding of the world. His past experiences facing bandits, rattlesnakes, and wildfires serve as survival guides for his grandson.

Papa is Leo's father who passed away from a fever a few months prior to the events in San Francisco. He served as the bridge between Grandpop's history and Leo's present, using bedtime stories to instill confidence in his son. His encouraging words continue to guide Leo's moral and survival choices on the streets.