Occupied France, 1942. Gilles (Nahual Perez Biscayart) is arrested by the SS and narrowly avoids execution by swearing to the guards that is not Jewish, but Persian. This lie temporarily saves him, before he is tasked with teaching Farsi to Klaus Koch (Lars Eidinger), the head of the concentration camp’s kitchen, who dreams of opening a restaurant in Iran when the war is over. Gilles, who knows not a word of Farsi, manages to survive by inventing words and presenting them as Farsi, teaching Koch what amounts to a nonsense language only they can understand. Their relationship sparks the jealousy of other prisoners and SS guards. Gilles knows he cannot keep the secret for long.