Twenty-seven thousand photos of corpses, and bodies tortured in detention centers of the Syrian regime, are leaked in 2014 by a mysterious deserter with the code name "Caesar". Because of the geopolitical interests of some countries and the indifference of other nations, international justice refuses to prosecute the regime of Bashar Al Assad responsible for crimes reminiscent of Nazi or Khmer barbarism. Filmed throughout Europe over nearly four years between 2016 and 2020, the film recounts the behind-the-scenes and twists and turns of investigations and proceedings that will lead to the issuance of arrest warrants for the highest officials of Bashar al Assad's administration for crimes against humanity.