Former fencing champion Waldemar Kant is killed in what seems a freak accident during a nightly training fight at the club with his best pupil, Boris Soetens. Commissioner Buitendam is on first name (Corneel) basis with both society families since his college days, to Vledder's sarcastic amusement. De Cock wants to know why widow Sofia Kant is as protective of Baris as his own father Max, while her son Ivar demands the killer be arrested. It turns out both families have secrets, one even a paternity matter which may be crucial for the fat inheritance.