In the film, three Jewish children fleeing the Nazis take refuge in a French convent. The children attend a boarding school run by a Catholic nun, Sister Gabrielle (Loretta Swit). The children arrive while the school is putting on a Nativity play, and in a quick act of thinking, Sister Gabrielle pretends the three children are her students. The Jewish children remain in the school for some time while the Nazis that are patrolling the area, led by an SS Major (Robert Joy), hunt for them in the forests surrounding the convent. Sister Gabrielle takes great lengths to keep the children's identities a secret, but the major is suspicious and continues to believe that they are likely hiding in the school.