On July 10, 1954, ten years to the day after the unsuccessful assassination of Hitler, the president of the Office for the Protection of the Constitution, Otto John, took part in commemorative ceremonies in Berlin. He disappeared the following night and reported from East Germany, denouncing in the media the rearmament of the Federal Republic as an obstacle to reunification. In 1955 he returned to the West where he was arrested and sentenced to four years' imprisonment. Did he betray his country or was he kidnapped and manipulated by agents of the GDR? Otto John explains himself in front of the camera of the great documentary filmmaker and historian of the Second World War, Erwin Leiser.