As the secondary narrator, Wendy is an aspiring writer working in the NYPL's "Remembrance" department in 1987. Her research into the Cards intertwines with her own journey of overcoming past trauma and building relationships.

A real historical figure and co-founder of CARD, Anne Morgan is characterized as an intimidating and commanding leader. Her generosity and intelligence drive many of CARD's initiatives.

Known as Dr. M.D., Anne Murray Dike is a co-founder of CARD and serves as a pragmatic counterpart to Anne Morgan. She ensures the organization runs efficiently with her focus on budget and records.

A group of women serving in CARD, each with unique roles and backgrounds, contributing their skills to support the war-torn French communities. Their camaraderie and resilience are central to the narrative.

A 15-year-old girl from a war-affected family, Marcelle becomes Kit's protégé and is inspired by the Cards' courage. Her journey reflects hope and resilience amid war's devastation.

Kit's boss at the NYPL, known for her pioneering work in children's library programs. She is critical and imposing, representing external pressures that challenge Kit's confidence.

Wendy's writing instructor, who is stringent in his critiques and represents an obstacle in Wendy's journey toward self-assurance in her writing career.

Kit's romantic interest, whose support helps her gain personal and professional confidence. His influence contributes to key developments in Kit's character arc.

A librarian and Wendy's love interest, Roberto is supportive and knowledgeable, aiding Wendy in her research and personal growth while emphasizing the importance of preserving cultural history.

Residents of the war-torn village, each character represents the different ways individuals cope with destruction and loss while rebuilding their community with the help of the Cards.