When the police bang on her family's door, 10-year-old Sarah Starzynski (Mélusine Mayance) shows all the self-possession of a grownup as she secrets her little brother in a closet, turns the key and then lies to the police more capably than her tongue-tied mother. But through the coming terror, she also shows the faith of a child, never wavering in her belief that she will escape her destiny in a Nazi camp and return to Paris to set her brother free.
Sarah's Key (rated PG-13 for disturbing scenes and themes) uncovers the buried history of Nazi-occupied France, when the French government arrested over 13,000 Jews and trapped them in a stadium for two days, with no water or toilets, before handing them over to Nazi death camps.
Sarah's story intertwines with the present-day story of Julia Jarmond (Kristin Scott Thomas), an American journalist who is writing about the deportment and begins to wonder how the fortunes of her own French family hinged on the plight of the Jewish people. Julia is also pregnant, after years of miscarriages and infertility, and throws herself into Sarah's story to forget that her husband doesn't want to be a dad again.
The film begins powerfully, dwelling not just on the physical misery but also the violence of a family being torn apart (the Starzynskis) and the tragedy of a family dissolving (Jarmond's). Sarah clings to a child's faith in people and in her own resourcefulness long after older people lose themselves in despair. The story loses some of its force midway when it buries Sarah's voice and lets other, less gripping characters finish telling her story.
In the end, the secrets Julia uncovers upturn her own family and the others whose past she dredges. But Sarah's story is not about what the living can glean from it-the lessons they can learn or the warnings they can take-but about history deserving to have its truth told, even if it disrupts the lives of the living.