Prof Quatermass (Sir John Mills) goes to London for a TV appearance. The city is now a 1970s Dystopia, a no-go area ruled by violent gangs.
Quatermass goes to stay at an Observatory run by Simon Macorkindale ( Relic Hunter Season 3 ). Unfortunately it is overrun by hippies, the Planet People, who want to get to the local henge, Ringstone Round.
Quatermass (Sir John Mills) finds a survivor among the Planet People at Ringstone Round, and tries to get her to a lab for tests. Unfortunately, once in the city they get caught in the middle of a gang war.
The Hippies are gathering at the Henge again. Can Mccorkindale get there in time to stop his family getting incinerated?
Professor Quatermass (Sir John Mills) finds refuge among some cellar-dwelling OAPs.
When Quatermass eventually contacts the government, they start to take counter-measures against the alien attack. The Prof thinks he has worked out what's causing the events at henges worldwide.
Quatermass (Sir John Mills) knows what is causing the events - and better still, he knows how to stop it. With the help of the Government he constructs a giant trap ...