Siegfried Kircheis is introduced by Michael von Keyserling to his old friend Christoph von Basel, a retired Vice Admiral. Kircheis notes that Basel continues to claim that he and his wife have only just arrived instead of the day before as revealed by Superintendent Hoffmann. Later the day while alone in a café, Kircheis finds a suspicious-looking man and begins to tail him. The man turns out to be a bait to trap Kircheis inside a flying ball court, where he faces five knife-wielding assailants. Kircheis holds off long enough before Hoffmann leads the local police to intervene...