In the second installment of the parodic Fantomas series, the title arch criminal and master of disguise kidnaps prominent scientist Prof. Marchand in order to develop a new powerful weapon to threaten the world. Fantomas is also planning to kidnap another scientist, Prof. Lefebvre. Journalist Fandor (Jean Marais, who also plays Fantomas and Prof. Lefebvre) decides to set a trap for the elusive villain. He disguises himself as Lefebvre and attends a scientific conference in Rome expecting Fantomas to kidnap him. As always, Fandor's ingenious plan backfires due to the interference of the bumbling police commissioner Juve (Louis de Funès).
by Yuri German synopsis