Abstract A prison diary written by Walter Koske, a documented member of the Nazi resistance. Walter Koske was one of twelve members of the illegal resistance cell Mix & Genest (named after the electronics company they worked for) who were arrested in 1937 for participating in communist party activities. Six of the arrested Mix & Genest members were sentenced to prison and six were released. Walter Koske (born in 1902), was arrested on his 35th birthday and charged with treason (...