On 7 November 1936, Madrid is about to fall into General Franco’s hands. A Russian squadron appeared above soon and supported by the international brigades, they managed to repel the attack. This film, based on testimonies tells the secret operation of Soviet pilots sent to fight in the Spanish Civil War. It centers on the Swiss aviator Ernst Schacht, commander of bomber squadron. On his return to Moscow, he was at first honored, and later executed on Stalin’s orders following the German attack on the USSR.