The Planet People's leader, Kickalong (Ralph Arliss), believes that the Planet People gathered at Ringstone Round have been transported, as promised, to the planet but it is clear to Quatermass and Kapp that they have been reduced to ashes. One survivor – a girl called Isabel (Annabelle Lanyon) who deliriously talks about "lovely lightning" – is found and is brought back to the Kapps' cottage. Making contact with NASA scientist Chuck Marshall (Tony Sibbald), they learn that thousands of young people have disappeared in similar incidents all around the world. Quatermass, aided by District Commissioner Annie Morgan (Margaret Tyzack), decides to bring Isabel to London for tests. As they make their journey, Quatermass speculates as to whether there is any connection between recent events and the decline in society. Reaching London, they are attacked by a gang. Quatermass is yanked from the car but Annie and Isabel manage to escape. Meanwhile, a large number of Planet People arrive at the radio telescope, congregating at the stone circle on its grounds. Working at a perimeter building, Kapp is horrified to see the light strike the area around his home – rushing home he finds his family gone.

As the president of a trashy TV channel, Max Renn (James Woods) is desperate for new programming to attract viewers. When he happens upon "Videodrome," a TV show dedicated to gratuitous torture and punishment, Max sees a potential hit and broadcasts the show on his channel. However, after his girlfriend (Deborah Harry) auditions for the show and never returns, Max investigates the truth behind Videodrome and discovers that the graphic violence may not be as fake as he thought.