The opening of Burning Bush has the look of a Sixties teen movie, with grinning kids gyrating to rock ’n’ roll – almost Beach Party without the beach. But the impression doesn’t last as the scene cuts to a caravan of tanks creeping along dimly lit streets and shortly into broad daylight. The kids are there too, but they’re not smiling. Some hurl Molotov cocktails at the tanks; others wave national flags (one smeared with blood). It’s real footage, and the place is Czechoslovakia, 1968, the end of the eight-month “Prague Spring” so poignantly symbolised by the young dancers who were briefly free enough to behave as Western youths do.