Lucy is a 63-year-old successful author who recently lost her second husband, David. Raised in extreme poverty in rural Illinois, she still struggles with feelings of invisibility and the lingering trauma of her childhood. Despite their divorce, she maintains a close, complex bond with her first husband, William, acting as a confidante when his life unravels.

William is a 71-year-old retired microbiology professor and parasitology researcher. He takes pride in his youthful appearance and physical fitness but struggles with profound insecurities and night terrors about his parents. When his much younger third wife leaves him and he discovers a hidden piece of his family history, he turns to Lucy for emotional stability and invites her on a trip to Maine.

Catherine is William's late mother, a woman who escaped deep rural poverty to build a middle-class life in Massachusetts. Originally married to a Maine potato farmer, she left her old life behind entirely to run away with a German prisoner of war. She presented a polished, fashionable exterior to the world, hiding her depression and secrets from her past.

Lois is a 73-year-old retired schoolteacher living in Houlton, Maine. Crowned Miss Potato Blossom Queen in 1961, she is proud of the stable, respectable life she built with her dentist husband and four children. She is fiercely protective of her peace and maintains a defensive pride about her rural origins.

Wilhelm is William's late father, a former German soldier who was imprisoned in Maine during World War II. He seduced Catherine by playing Brahms on a piano in her home, eventually taking her to Massachusetts to start a new life and study at MIT. His imposing aura of authority and his wartime past cast a long shadow over his son's life.

Estelle is an actress and William's third wife, more than twenty years his junior. She is lively and whimsical but eventually grows bored with their marriage, abruptly leaving him and taking their young daughter and most of their furniture. Her departure initiates William's crisis of identity.

David is Lucy's late second husband, a cellist who formerly belonged to a Hasidic Jewish community before his family cut him off. He provided Lucy with a deep sense of security and shared her understanding of poverty and isolation.

Chrissy is the adult daughter of Lucy and William. She faces personal heartbreak when she suffers a miscarriage shortly after announcing her pregnancy. She is protective of her father after Estelle leaves him and maintains a close, open relationship with her mother.

Becka is the adult daughter of Lucy and William. Along with her sister Chrissy, she is outraged by Estelle's sudden departure and steps in to support her father and her young half-sister during the family crisis.

Bridget is the 10-year-old daughter of William and Estelle. Her existence was a surprise to William, who had not wanted more children, but he loves her deeply because she reminds him of his older daughters.

Clyde Trask is a potato farmer in Maine who later becomes a Republican state legislator. He was much older than Catherine when they married, and she eventually left him for a German prisoner of war.

Joanne is William's second wife and a former mutual friend of William and Lucy. She engaged in a six-year affair with William during his first marriage, but their eventual marriage soured because she felt she missed her chance to have children while acting as his mistress.

Pam is a divorced woman who attends William's 70th birthday party. She strikes up a presumptuous conversation with Lucy about lingering feelings for ex-husbands, hiding her own romantic history with William.

Marilyn Smith was Clyde Trask's long-term sweetheart before Catherine came between them. After Catherine abandoned her past in Maine, Marilyn stepped in to raise Lois, eventually leaving her a large ancestral home in Houlton.

Richard Baxter is a highly successful parasitologist whom William views as a professional rival. William obsesses over Baxter's origins during his road trip, using the rivalry to channel his own feelings of inadequacy and aging.

Robbie is a man Lucy dated for three months following her separation from William and her father's death. Nicknamed "Park Avenue Robbie," he initially frightened Lucy with his intensity but provided a temporary connection during a vulnerable period.

Mrs. Nash is Lucy's former high school guidance counselor. She played a crucial role in helping Lucy escape her rural poverty, assisting her with college applications and taking her shopping for clothes so her working-class origins would be less obvious.

Phyllis is a local librarian in Houlton, Maine. She assists William and Lucy by showing them historical photographs of German prisoners of war who were sent to the town, and she enthusiastically recognizes Lucy as a published author.

Ralph is Phyllis's husband and a local resident of Houlton. He serves as a spontaneous historical guide for Lucy and William, showing them what remains of the town's prisoner of war barracks during their visit.