As a Polish Catholic social worker in the early 1940s, Irena Sendler created and led a conspiracy of women who moved in and out of Warsaw's Jewish Ghetto disguised as nurses employed by Warsaw's Health Department. Though they worked under the guise of merely attempting to prevent and contain the spread of Typhus and Spotted Fever, Sendler and her brave cohorts emerged each time with the children of consenting Jewish parents. The children were sometimes sedated and hidden inside boxes, suitcases and coffins as a means of rescuing them from their imminent deportation to death camps. They were given new identities and placed with Polish families and in convents. Sendler kept a hidden record of their birth names and where they were placed with the hope that they would some day be reunited with their own families.

In 1943, the Nazis discovered Sendler's daring and dangerous ruse and arrested her. She was tortured by Gestapo agents and suffered broken feet. On the day of her scheduled execution she was rescued by "Zegota," the underground network with which she worked to save the Jewish children.

As a result of Sendler's efforts, approximately 2,500 children were smuggled to safety. Not a single child she rescued was ever betrayed or discovered by the Nazis.