In July 1981, violence explodes in east London, Bradford and Southall. In Walthamstow, Mrs Parveen Khan and her children are killed in their home in an arson attack. The situation in Southall ignites when hundreds of far-right skinheads descend on the Hambrough Tavern. The Southall Youth Movement clash with the skinheads and burn the pub down. In Bradford, rumours of a National Front attack lead to 12 young people stockpiling petrol bombs. When the police arrest them on conspiracy charges, they face life imprisonment. They must persuade a jury that the petrol bombs are weapons not of aggression but of defence against a concerted far-right assault on their community. The case becomes a rallying call for the Asian communities in the UK with the slogan 'Self defence is no offence', and the outcome of the trial changes the country.