The Earth has fallen into apocalyptic ruin, and a terrifying alien force is destroying the youth of England! Welcome to the 1970s Quatermass mini-series, based on the mega-awesome Quatermass movies, starring (you guessed it) the genius Professor Bernard Quatermass. In this clip the good professor tries to talk some sense into the alien-worshiping hippie youth, but their Black Sabbath-esque leader intervenes.
And of course the nasty hippies get what they deserve for thinking that aliens will take them to another planet. As the series progresses, the whole Stonehenge/evil aliens connection develops further and Quatermass is right in the middle of it using his magnificent brain. And, for some reason, a menorah.
Quatermass Series [via IMDB]