Dominic is an orphaned fifth-grader who has bounced between foster homes since infancy. Lacking friends and ashamed of his orphaned status, his only physical connection to his past is a dull gold key bearing the initials "S.C." that belonged to his parents. He is deeply lonely but resourceful, struggling with feelings of rootlessness until an inexplicable event transports him to 1908 Italy.

Francesco is the eldest of the orphaned Candiano brothers living in rural 1908 Italy. Following the loss of his parents, he serves as the leader and caretaker for his younger brothers in the village of Avaletto. He prioritizes family unity above all else, enforcing a strict code of sharing and mutual support to help them survive constant poverty and hunger.

Salvatore is the ten-year-old middle brother of the Candiano family. Living in a barn and tending a landowner's fields for survival, he possesses a boisterous and adventurous spirit. He wears a gold key that he found in a graveyard, hoping it will one day open a chest of buried treasure, and he is fiercely willing to fight those who mistreat his family.

Antonio is the seven-year-old youngest brother of the Candiano family. Growing up in extreme poverty in Italy, he relies completely on his older brothers for food and protection. He represents hope for his older siblings, who endure harsh conditions to ensure he has a chance at a better future.

Father Tomaso is the beloved village priest in Avaletto, Italy. He operates within a broken social system that provides no formal safety net for unhoused children. He does his best to feed the Candiano brothers and actively works to arrange their passage to America so they can escape their bleak circumstances.

Dave is a social worker assigned to Dominic's case in New York City. He serves as the single consistent adult presence in the young boy's life. He works tirelessly within an underfunded foster care system to find a stable home for Dominic.

Violetta is a goat belonging to the Candiano brothers. In addition to being a cherished pet, she provides the impoverished boys with essential nourishment through her milk.

Tibero is a mountainous security guard who works for the wealthy landowner in Avaletto. Known for aggressively whipping suspected thieves, he acts as a brutal enforcer of the local class structure.

Sausage is the son of the wealthy local boss in Avaletto. He uses his elevated social status to bully the impoverished Candiano brothers, throwing rocks and manure at them.

Tullio is Sausage's cousin. He accompanies Sausage to mock and abuse the orphaned boys for smelling bad and stealing cherries.

Nina is a local girl in the village of Avaletto. She seeks out the Candiano brothers to deliver a message that Father Tomaso is looking for them.

Pasquale is a contact of Father Tomaso located in the city of Naples. He provides the boys with a meal of octopus and strange religious relics during their journey.

Signora Giasullo is a friend of Father Tomaso in Naples. She provides the boys with a meal and a place to stay while they prepare for their voyage to America.