Isabella is an outspoken, cosmopolitan 21-year-old from New York who feels isolated within Boston's rigid high society. She desperately longs for a sense of purpose and motherhood. A passionate, idiosyncratic woman, she channels her frustrations into interests like architecture, botany, book collecting, and visual art, often resisting the gendered expectations of the late 19th century. Her massive wealth allows her to pursue her eccentricities and eventually become an influential cultural patron.

A wealthy, mild-mannered Boston businessman who is devoted to his wife but sometimes struggles to understand her unconventional behavior. He values social propriety and is far more comfortable with the city's traditional expectations than Isabella is. Despite their differences in temperament, he supports her through emotional hardships and shares her growing interest in travel and art.

The eldest of Jack's nephews, who eventually comes under the guardianship of Isabella and Jack. Joe is a sensitive and melancholy young man who struggles with feelings of isolation and questions his ability to fit into society. He shares a close bond with his aunt, who tries to nurture him and help him find an accepting community.

Jack's sister and Isabella's former boarding school friend. Unlike Isabella, Julia is calm and passive, willing to accept the expectations placed upon upper-class women. She focuses primarily on domestic life and motherhood, creating a contrast in values that sometimes strains her friendship with her sister-in-law.

A handsome, charismatic American writer who easily captures attention in social settings. He sees Isabella as a muse and an object of desire, confidently pursuing a connection with her despite her marriage. Though deeply affectionate, he often prioritizes his own comfort and convenience over the emotional wellbeing of others.

The wife of Jack's brother, Joseph, and one of Isabella's few true friends in Boston. She is an established member of the local high society who tries to help Isabella understand its unwritten rules. She is a dedicated mother and a warm, supportive presence in Isabella's early married life.

Jack's brother who resides in Boston. He is the father of Joe, Amory, and Gus, maintaining a standard upper-class household with his wife Harriet. His family provides Isabella with regular social interactions and visits.

The infant son of Isabella and Jack Gardner. His arrival brings immense joy to Isabella, seemingly answering her deep longing for motherhood and purpose. He is a central focus of her early married years.

A gardener at the Boston Public Gardens who shares Isabella's keen interest in botany. He treats her as an equal and encourages her independence. He becomes one of her first unconventional friends outside her elite social circle.

A scientist and museum founder who has traveled extensively to collect specimens. He respects Isabella's sharp intellect and invites her to engage with academic circles at Harvard. He forms a bond with her over their shared personal griefs.

An art historian and Harvard professor who introduces Isabella to rare books and intellectual discourse. His translation work inspires her early passion for collecting rare literary texts. Their correspondence fuels her growing interest in European art and history.

A young art historian who assists Isabella in acquiring European artworks. He faces discrimination due to his Jewish heritage, but Isabella values his expertise. She provides him with financial patronage to travel and secure art on her behalf.

A prominent Anglo-American writer who becomes a close confidant to Isabella. He corresponds with her frequently, offering a sympathetic ear for her complex emotions and unconventional desires. He introduces her to prominent artists in Europe.

A renowned American painter commissioned to paint Isabella's portrait. The painting sessions create an intimate dynamic between them. He produces a striking and controversial portrait that challenges the modest expectations of Boston society.

A Swedish painter whose work Isabella admires at the Chicago World's Fair. He travels to Venice with his wife at Isabella's invitation. He works on a portrait of Isabella during their time in Italy.

One of Isabella and Jack's nephews who comes under their guardianship. He spends his summers at the seashore with his newly expanded family. He grows up surrounded by his aunt's growing art collection.

The youngest of the three nephews taken in by Isabella and Jack. He is raised in a household increasingly devoted to art and intellectual pursuits. He is cared for deeply by his aunt and uncle.

A young waiter working on the transatlantic ship taking Isabella and Jack to England. He helps Isabella recognize a sense of kinship with those who live on the margins of society. He introduces her to the freedom enjoyed by those outside the upper class.

A young woman and feminist thinker who corresponds with Isabella. She suggests travel locations and shares her intellectual pursuits. She is part of the broader circle of progressive women Isabella eventually connects with.

A celebrated writer who meets Isabella at a Boston party. He encourages her to realize that she can create her own accepting social circle rather than seeking approval from elite traditionalists. His unabashed lifestyle inspires her growing independence.