The play features a middle-aged middle-class couple living in a north London suburb whose life has been catastrophically affected by a hit-and-run accident which has left their beautiful undergraduate daughter totally dependent upon them.
For two years, Tom and Amy Bates have been struggling to cope with their altered lives, after their daughter Pattie (or Patricia) was severely injured in a hit-and-run accident.
Although poorly educated and gullible, Amy firmly believes that Pattie is able to understand what is being said in her presence, whereas Tom has given up all hope of her recovery.
However, when Martin tries to rape the disabled girl again after Tom and Amy have gone to bed, Pattie starts screaming so loudly that he runs out of the house.
The original 1976 play was withdrawn shortly before its scheduled transmission (despite being listed in the Radio Times) because then Director of Television Programmes Alasdair Milne found it "nauseating" though "brilliantly made".
Rewritten by Potter for the stage, the play premiered on 11 October 1977 at the Crucible Theatre, Sheffield and transferred to the West End the following year.
In the introduction to the play script, published in 1978, Potter recalled that "the BBC received several letters of congratulation for 'taking a stand' against the rising tide etc.
Justifying the play, he wrote: "Brimstone and Treacle is an attempt both to parody certain familiar forms of faith and yet at the same time to give them expression.
Years of acute psoriatic arthropathy — unpleasantly affecting skin and joints — had not only taken their toll in physical damage but had also, and perhaps inevitably, mediated my view of the world and the people in it.
[...] I was engaged in an extremely severe struggle, not so much against the dull grind of a painful and debilitating illness, but with unresolved, almost unacknowledged "spiritual" questions.