Kristin Scott Thomas plays an American reporter living in Paris whose obsession with the story of Sarah - a young girl caught in the notorious Vel' d'Hiv round-up of French Jews in 1942 - hits closer to home than she had ever imagined. As the two threads of Tatiana de Rosnay's bestseller gradually intertwine, writer-director Gilles Paquet-Brenner exposes a catalogue of personal secrets and tragedies against the backdrop of one nation's shame.