Spirou and Fantasio, paying the Count of Champignac a visit, discover that he is hiding an imposing visitor: a towering Russian genius who has created an anti-gravity ray. Unfortunately, the KGB is already hunting him, because he's decided he wants to keep his invention secret. And to make things worse, his former associate, who knows almost as much as he about the ray, has been captured by Chinese authorities. Spirou decides it is vital to free the prisoner...