Sarah's Key is culled from a popular novel (by Tatiana de Rosnay) set during the Holocaust and the Nazi occupation of France. The main character, an American magazine writer (Kristin Scott Thomas) living in Paris, discovers that her husband's family acquired their home after the Jews who once lived there were sent to an abandoned stadium, where they endured three hellish days before the Nazis transported them to the camps. The writer becomes convinced that Sarah, the family's little girl, escaped, and she tries to follow her trail.
The narrative reveals an obscure piece of history in which the French comported themselves like the SS. Sarah's is a fictional horror story centered on the trauma of a child who is haunted by an impulsive action she took in an effort to save the life of someone she loved. But it might easily have happened. Sarah's Key isn't an especially good movie, but it's touching and very well acted (especially by Thomas and by Niels Arestrup and Dominique Frot in flashbacks as a farmer and his wife). It doesn't cheapen its subject by manipulating either it or us.