A high-ranking Nazi official tasked with overlooking East Prussia. A real person, in the book he collaborates with Florian and Dr. Lange to repair and consolidate European art and artifacts stolen by the Nazis. He appears primarily in Florian’s memories of the past for the first two thirds of the novel, but nearly exposes Florian’s true identity in the final chapters. The Blonde Nazi who checks Florian’s papers as he boards the Wilhelm Gustloff is suspicious of Florian, and so sends a wire to Koch verifying that he knows the teenager. Koch responds that he does, but also wants to know where the key to the Amber Room is, causing Florian to fear that Koch will track him down.