Der Weg ins Nichts(1976)

In 1923, Judge Böhnsdorf and Inspector Dumke convict 22-year-old Fritz Bondersen of treason, accused of selling military secrets on the testimony of General Director Gotthardt, and sentence him to 15 years in a Zuchthaus. Despite his protestations of innocence, Bondersen can’t produce proof. Two years later, his fiancée Edith Volkmann, aided by journalist Günther Borchert, tracks down a French officer whose eyewitness account could discredit Gotthardt’s statement. Their quest to expose a massive fraud offers Bondersen a final hope for justice.