Upon reading their mother's will, Jeanne and Simon Marwan are given two envelopes: one intended for a father they thought was dead and the other for a brother they did not know existed.
Jeanne sees in this enigmatic legacy the key to her mother's silence, who was locked in an unexplained mutism during the final weeks before her death. She immediately decides to leave for Moyen Orient to exhume the past of this family about which she knows almost nothing...
Simon, for his part, cares little for the posthumous whims of this mother who was always distant. But his love for his twin sister will soon push him to join Jeanne and travel with her through the land of their ancestors on the trail of a mother very different from the one they knew.