"Underground" was a science-fiction television play presented as part of the British anthology series Armchair Theatre which was broadcast live by the ITV commercial network on 30 November 1958.
Written by dramatist James Forsyth (1913–2005)[2] and based on a novel by Harold Rein,[3] the play depicted survivors from a nuclear holocaust living in the London Underground.
[4] It featured actors Donald Houston, Ian Curry, Patricia Jessel, Warren Mitchell, Peter Bowles and 33-year-old Gareth Jones[5] in what would be his last role.
The actors started making up lines, 'I'm sure if so-and-so were here he would say'..."[6][7] Producer Sydney Newman instructed director Ted Kotcheff to continue with the play and "shoot it like a football match", meaning to follow the characters around as they improvised a way of coping with the missing cast member.
Kotcheff hurriedly re-structured the story[8] during a commercial break[9] in order to be able to bring the play to an end without the missing character being noticed by the audience.