Hans Niemann is launching a counterattack in his dispute with chess world champion Magnus Carlsen, filing a federal lawsuit that accuses Carlsen of maliciously colluding with others to defame the 19-year-old grandmaster and ruin his career.
It's the latest move in a scandal that has injected unprecedented levels of drama into the world of elite chess since early September, when Carlsen suggested Niemann's upset victory over him at the Sinquefield Cup tournament in St. Louis was the result of cheating.
