After a devastating disaster, a major city lies in ruins. Cesar (Adam Driver), a brilliant architect and inventor of the miraculous material Megalon, wants to build a utopian city where people can be truly happy. But his idealism provokes resistance, especially from those in power including Mayor Cicero (Giancarlo Esposito) and the populist Clodio. Meanwhile, Julia, the mayor’s daughter, searches for the meaning of her life.