 De Gier s crazy neighbor, Walther Steenman, claims that someone is trying to assassinate him. De Gier doesn t believe him, but then he and Grijpstra find a bullet hole in his house, and his wife is hospitalized after a car ran into her. It turns out that he is being mistaken for a prime witness in a trial against a top criminal. Grijpstra and De Gier want to help him, but are troubled by higher-ups who are afraid they will hamper the case against the criminal. A missing file turns up in Hetty s purse.