Ahead of a timely re-airing of Mick Jackson’s famously bleak, rarely seen docudrama, its director recalls why he unleashed a mushroom cloud on Sheffield in 1984, while our writer explores the film’s lasting legacy

One Sunday night in September 1984, between championship darts and the news with Jan Leeming, the BBC broadcast one of its bravest, most devastating commissions. This was Threads, a two-hour documentary-style drama exploring a hypothetical event deeply feared at the time and also somehow unthinkable: what would happen if a nuclear bomb dropped on a British city.

Made by British director Mick Jackson with Kes author Barry Hines, and set in Sheffield, it begins with a young couple, working-class Jimmy and middle-class Ruth, dealing with her unexpected pregnancy in familiar kitchen-sink drama surroundings. International tensions build slowly in the background as the minutes tick by, bursting in through newspaper headlines, radio and TV news, and the...