From en.wikipedia.org'Aliens harvest hippies for food' - a truly wonderful plot.
Quatermass (TV serial)
Quatermass (also known as The Quatermass Conclusion or Quatermass IV) is a British television science fiction serial produced by Euston Films for Thames Television and broadcast on the ITV network in October and November 1979. Like its three predecessors, Quatermass was written by Nigel Kneale. It is the fourth and final television serial to feature the character of Professor Bernard Quatermass.
Influenced by the social and geopolitical situation of the early nineteen-seventies and the hippie youth movement of the late nineteen-sixties, Quatermass is set in a near future in which large numbers of young people are joining a cult, the “Planet People”, and gathering at ancient sites, believing they will be transported to a better life on another planet. The series begins with Professor Quatermass arriving in London to look for his granddaugher, Hettie Carlson, and witnessing the destruction of two spacecraft and the disappearance of a group of Planet People at a stone circle by an unknown force. He investigates this force, believing that Hettie may be in danger. As the series progresses, it becomes apparent that the Planet People are being harvested for food by an alien force. Professor Quatermass must devise a way to destroy the aliens before many more people die.
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