As I got to know my fictional Polish resistance member, Maria, I studied Church of Spies by Mark Riebling. The Vatican’s position on Nazism remains heavily disputed, but this fascinating account is rich with primary sources detailing work Pope Pius XII did in secret to combat the Nazis and overthrow Hitler—though his intended plot ultimately failed. To learn more about occupied Warsaw and the Polish resistance, I relied on Irena’s Children: The Extraordinary Story of the Woman Who Saved 2,500 Children from the Warsaw Ghetto by Tilar J. Mazzeo, the story of a Polish woman named Irena Sendler who smuggled Jewish children from the Warsaw Ghetto and is credited with saving more than two thousand five hundred lives. Through Sendler’s work, she crossed paths with Mother Matylda Getter and the Franciscan Sisters of the Family of Mary. Although many of the details included about the sisters and resistance are factual, my portrayal has been condensed and fictionalized for story purposes.

Maria told me very quickly that she was a chess player, and I soon realized that chess would play a central role in her story. By diving into chess history, I discovered women such as Vera Menchik, who won the first Women’s World Chess Championship in 1927, defended this title six times, and, in 1944, was killed alongside her sister and mother in a V-1 bombing attack on London. She was thirty-eight years old and remains the record holder as Women’s World Chess Champion, with a seventeen-year title. In researching Auschwitz, I learned about Maria Mandel’s prized creation: the Women’s Orchestra, comprising Jewish women who were spared death but forced to entertain their captors through music and play for roll calls, selections, transports, and executions. I combined these concepts for my reasoning behind why Maria, a girl sent to Auschwitz while it was a prison camp for men, would be spared: the camp deputy, Karl Fritzsch, described by historians as a man who resented authority and often broke rules, was not always under the watchful eye of Kommandant Rudolf Höss, who was a firm believer in order and obeying superiors, as indicated in his autobiography, Commandant of Auschwitz. In my story, Fritzsch rebels by registering Maria, a female, so he can force her to play chess to entertain the SS guards.