Young school teacher Andrée Geulen secretly defies the Nazis in Belgium, who are forcing Jews to wear a yellow Star of David. Andrée is not Jewish, but she feels a maternal connection to her students, who are living in constant fear, and decides to take action. No child should have to suffer under such persecution. But what can one woman do against an entire army?

Ida Sterno is a Jewish woman who works with a clandestine resistance group tasked with hiding children from the Gestapo. She recruits Andrée because her Aryan appearance can provide crucial security measures for their efforts. Andrée agrees to join and begins work immediately by adopting a code name: Claude Fournier.

Together, Andrée and Ida work tirelessly to move Jewish children from their families and smuggle them to safety through the secret channels established by the Committee for the Defense of Jews. As each child is hidden, Andrée commits to memory their true name and history. Someday, she vows, she will help reunite many of these families as she can.

But with the Gestapo closing in along with traitorous Fat Jacques, who has turned from ally to enemy and is threatening to identify any Jew he meets, Andrée and Ida must work against increasingly impossible odds to save as many children as possible and keep them safely hidden—even if it might cost them their own lives.