What makes Megalopolis so strange and, for a big-budget Hollywood film, so singular, is that, just like Vergil’s Aeneid, it is at once accretive, allusive, and idiosyncratic because Coppola is attempting something very few artists have ever done: to speak from inside the imperial organism, even as it begins to crack, and to craft a vision that is both a monument to its grandeur and a requiem for its decline.