Johnny is a 14-year-old apprentice silversmith living in Boston in 1773. Highly skilled at his craft, he effectively runs his master's shop and secures important commissions. His exceptional talent makes him arrogant, leading him to boss around his fellow apprentices and members of the Lapham household. After a severe burn damages his right hand, he must abandon his chosen career and find a new way to survive in the city.

Cilla is the 11-year-old second-youngest granddaughter of Mr. Lapham. She works hard around the house and cares deeply for her frail younger sister, Isannah. Her family intends for her to marry Johnny and inherit the silver business, an arrangement she accepts. She possesses a sharp tongue and frequently checks Johnny's ego with well-timed insults, but she remains steadfastly loyal to him when he faces trouble.

Rab is a tall, powerfully built 16-year-old apprentice at his uncle's printing office. He stands out due to his dark hair, dark eyes, and extremely calm, unhurried demeanor. As a member of the semi-secret Sons of Liberty, he possesses deep political convictions and valuable connections throughout Boston. He shares his food with Johnny and quickly becomes a stabilizing, encouraging force in the younger boy's life.

Mr. Lyte is an affluent, powerful merchant who trades in imported goods. He is known for trying to profit from both the Whigs and the Tories in Boston's escalating political conflict. When Johnny approaches him with a silver cup bearing the Lyte family crest, the merchant proves fiercely protective of his wealth and actively tries to have the boy imprisoned rather than acknowledge any kinship.

Dove is a pale, out-of-shape 16-year-old apprentice in Mr. Lapham's shop. He has been apprenticed longer than Johnny but possesses far less skill, leading to a deep, simmering resentment. Lonely and lacking any known family, he bears the brunt of Johnny's verbal abuse and constant orders. He resorts to underhanded tactics to get back at the younger boy, resulting in a disastrous practical joke.

Mr. Lapham is an elderly master silversmith whose business is slowly dwindling. He acts as the patriarchal head of his daughter-in-law's crowded household. Deeply pious, he values religious humility far more than worldly success or financial security. He tries repeatedly to correct Johnny's arrogance by assigning him Bible verses about the dangers of pride.

Mrs. Lapham is Mr. Lapham's practical, hard-working daughter-in-law. She manages the cooking, cleaning, and daily logistics for seven people living in a state of near-poverty. Her primary concern is the financial survival of her four daughters, causing her to view Johnny entirely in terms of his economic usefulness to the family business.

Isannah is the eight-year-old youngest daughter of the Lapham family. She is frail and frequently falls ill, requiring constant attention from her older sister Cilla. Despite her health issues, she possesses an angelic beauty with striking blonde hair that draws attention from wealthy, upper-class Bostonians.

Lavinia is Mr. Jonathan Lyte's beautiful, elegant daughter. Freshly returned from living in England, she commands attention across Boston with her high fashion and striking features. She represents the peak of Tory high society and enjoys the privileges that her father's massive wealth affords her.

Mr. Lorne is Rab's uncle and the owner of the Boston Observer printing office. He publishes a newspaper highly sympathetic to the Whig cause, openly defying the British governor's orders to cease seditious printing. He provides Johnny with a job delivering papers and a new place to live in the office loft.

Mrs. Lorne is Rab's aunt by marriage and Mr. Lorne's wife. She is a warmhearted, observant woman who bakes sweets for the apprentices. She quickly notices Johnny's lonely nature and goes out of her way to make him feel comfortable in his new home.

Dusty is the 11-year-old youngest apprentice in Mr. Lapham's silversmith shop. He looks up to Johnny and generally follows his orders without complaint, though he is easily swayed by the older boys' ongoing rivalry.

Madge is the 18-year-old eldest daughter of Mrs. Lapham. She has a rough, boisterous, and good-natured personality, frequently helping her mother manage the physically demanding chores of the large household.

Dorcas is the 16-year-old second eldest Lapham daughter. Despite her family's poverty, she longs for a life of wealth and desperately tries to imitate the mannerisms and clothing of elegant, fashionable high-society women.

Paul Revere is Boston's most accomplished master silversmith and a prominent leader among the Whigs. He possesses a prosperous shop separate from his home, representing the pinnacle of the career Johnny hopes to achieve. He also organizes spy networks to monitor British troops.

Sam Adams is a passionate, highly influential political leader striving to stir up resistance against British rule in the colonies. He relies on local printers and young messengers to organize secret meetings, such as the Boston Observers, and orchestrate large-scale protests.

Mr. Tweedie is a 40-year-old journeyman silversmith whom Mrs. Lapham brings to Boston to save the family business after Johnny's accident. He is a timid, cautious man who insists on marrying one of the Lapham daughters as part of his business contract.

Mrs. Bessie is a Black woman who serves as the cook and housekeeper for the wealthy, Tory-leaning Lyte family. Despite working for staunch loyalists, she quietly supports the Whigs and uses her position to gather information for the Sons of Liberty.

Lieutenant Stranger is a young, skilled British officer stationed in Boston. He shares Johnny's deep love of horses and offers to teach the boy advanced equestrian tricks. Their relationship highlights the complex, humanizing bonds that form across enemy lines.

Pumpkin is a kindly, low-ranking British private who secretly sympathizes with the American colonists. Coming from a poor background in England, he dreams of deserting the army to buy a small farm in the colonies, something his social standing would never allow back home.

Goblin is a pale, skittish horse with glassy blue eyes and a mahogany mane. He is used by the printing office to deliver newspapers to the surrounding towns. Because the horse is easily frightened, riding him requires immense patience and skill.