At 3:18pm, on June 3rd 1991, a pyroclastic flow – a cloud of superheated gases and particles – descended at over 100mph from the peak of the Unzen volcano in Japan, consuming everything in its path. It instantly killed Katia and Maurice Krafft, volcanologists and filmmakers from France. They were too close. They were almost always too close. The Kraffts left an archive of over 200 hours of footage, unprecedented in its spectacular and hypnotic beauty. Werner Herzog, who had access to the entire archive, created a film that cannot be categorized. It is not a biography. It is a rather a requiem celebrating the legacy of Katia and Maurice Krafft.