"Cause of Death Unknown" - Carola Neher (1900-1942) actress, singer and feminist. Brecht wrote the role Polly Peachum for her. She practiced boxing with Marlene Dietrich. After Hitler seized power, thousands of German communists and anti-fascists fled to the Soviet Union, the "fatherland of the working people". The tragedy of German communism is that the vast majority of them perished or were lost during Stalin's "cleansing". Carola Neher is one of the fate figures of that time. In the 20s, she belonged to the narrow circle of Brecht actresses. The film accompanies her son Georg Becker in search of his mother's traces in the sinking Soviet Union.