Science fiction is never about the future, in the same way history is rarely about the past: they're both parable formats for examining or commenting on the present.
I walk up a dune to a beach and look out to sea, but it's 100km away. The ships lie askew in their dry beds, at anchor for ever. Today is my son's birthday. Thousands of miles from here, his healthy lungs are blowing out candles. I should be there but I'm here with another boy, who puts his face close to mine and laughs. I smile back but realise he can't see it, because I'm wearing an antiseptic muzzles to protect me from his breath.
Beautifully shot, impeccably paced, it was a clear, unrelenting look at the National Trust, its friends and enemies, and it makes you want to burn your passport and beg the Luftwaffe to have another go.