Caroline is a 37-year-old former Broadway actress living in New York City. She volunteers long hours at the French Consulate and manages the French Families Fund, a charity that sends comfort boxes to orphans overseas. She often leverages her high-society connections to fund her initiatives, preferring philanthropic work over the traditional socialite lifestyle. She continues to grieve the loss of her father while caring for her widowed mother.

A 16-year-old Polish girl whose normal life in Lublin shatters upon the German invasion. Trained in first aid through the Girl Guides, she quickly joins the underground resistance to sabotage the occupying forces. She possesses a fierce loyalty to her family and friends, taking dangerous risks to protect the people she cares about in an increasingly hostile environment.

A 25-year-old German medical student who ardently supports the Reich. Despite her ambition to become a surgeon, national policies forbid women from specializing in the field. Seeking to escape an abusive home environment with her uncle, she accepts a medical position at the Ravensbrück reeducation camp, where she aligns her medical practice with the brutal directives of the regime.

A handsome French Broadway actor currently working in New York. He accepts a speaking engagement at the French Consulate and quickly forms a close bond with Caroline Ferriday. Though he has a wife in France, he feels a strong romantic connection to Caroline as the threat of war looms over his home country.

A young Polish boy who participates in the local underground resistance. He takes his duties seriously and attempts to protect his friends from the escalating violence in Lublin. He harbors deep feelings for Kasia and feels a heavy burden of responsibility for the safety of his peers.

Kasia's older sister, who has recently completed medical school and prepares for her pediatric residency when the invasion begins. She immediately volunteers at the local hospital. She acts as a calming and protective presence for Kasia when their family faces danger.

Kasia and Zuzanna's mother, a beautiful woman with blonde hair and a talent for sketching portraits. Known to her family as "Matka," she initially believes her part-German heritage will keep the family safe. She is deeply protective of her daughters and attempts to shield them from the occupying soldiers.

A cruel guard at the Ravensbrück camp. She wields authority with viciousness, frequently using her dog to terrorize the prisoners. She represents the direct, daily threat to the women confined within the camp's walls.

Paul's wife, who operates a lingerie shop in Paris. Described as incredibly beautiful and significantly younger than Paul, she remains in France as the political situation deteriorates. Her marriage is strained even before the outbreak of the conflict.

A child connected to Paul and Rena Rodierre. She grows up in France and eventually becomes a child actress, playing a part in the continuing connections between the families separated by the war.

Caroline's boss at the French Consulate in New York. He manages the political sensitivities of the consulate's public events, attempting to avoid offending isolationist politicians. He is practical and supports Caroline's work, though he cannot offer her a paid salary.

A child connected to Kasia and Pietrik. She demonstrates a keen interest in art and bears a striking physical resemblance to Kasia's mother, carrying forward the family's artistic talents in the aftermath of the conflict.

Pietrik's sister, a young Polish girl who wears braces. She is swept up in the arrests in Lublin and transported to Ravensbrück. She finds herself navigating the brutal conditions of the camp alongside the Kuzmerick women.

Kasia and Pietrik's best friend in Lublin. Because of her Jewish heritage, she faces immediate danger and prejudice from neighborhood children and occupying forces. She relies on her friends for protection as the political climate grows hostile.

Kasia and Zuzanna's father, affectionately called "Papa." He works at the postal office and quickly takes action to hide valuable family items when the invasion begins. He attempts to secure his family's safety and communicates with Kasia through careful methods.

Caroline's high-society best friend in New York. She questions Caroline's intense dedication to volunteer work and encourages her to focus on marriage and social engagements. She provides a connection to the wealthy circles Caroline navigates for her charity funding.

Caroline's former romantic partner and Betty's brother. He works at the State Department and maintains a possessive, lingering interest in Caroline despite being married to another woman. He represents the comfortable, socially acceptable life Caroline has rejected.

Herta's father, who suffers from a severe illness. He relies on the kindness of a local Jewish doctor and strongly disapproves of the rising Nazi party. He questions Herta's lack of empathy and worries about the future of Germany under the current regime.

Herta's mother, a woman who takes pride in her Aryan blood and openly supports the Reich. She frequently calls Herta "little heifer" and enthusiastically benefits from the displacement of Jewish citizens in their community.

Herta's uncle, who runs a local butcher shop. He exploits Herta's dependence on his family for her education funding, subjecting her to sexual abuse. His actions drive Herta to seek employment far away at a reeducation camp.

Herta's former university cohort mate who works as a doctor at the camp. He introduces Herta to the brutal realities of their duties. He eventually struggles with the ethical implications of their work and leaves his position.

The chef who works for Caroline's family. He assists with the catering for their social and charitable gatherings in New York, and he maintains a steady, helpful presence in the Ferriday household.

A member of the Polish resistance who provides refuge for those fleeing the occupying forces. She later crosses paths with the Kuzmerick sisters under dire circumstances, continuing to offer support and education to her peers.

The commanding officer at Ravensbrück. He is highly skeptical of having a female doctor on staff, preferring men for the rigid environment of the work camp, but Herta manages to convince him to let her stay.