Potter's most controversial script (it was shelved at BBC for eleven years), Brimstone and Treacle inverts a Potter theme, the visitation drama in which the arrival of an unexpected guest sets in motion a series of unpredictable events. This time the guest is not an angel, but actually a demon. Martin, an accomplished con-man, disrupts the claustrophobic routines of the Bates family whose voluptuous daughter has been paralyzed in an accident. The hypocritical Mr. Bates (Denholm Elliot) is guilt-wracked over the deplorable state of his daughter while the ever-optimistic Mrs. Bates sees this tragedy as a test of her spirit. For Potter, the black-humored play is "an attempt both to parody certain familiar forms of faith and yet at the same time to give them expression....The guilty and unhappy father asserts in his torment that 'there is no God and there are no miracles' and the mother's God 'is a creature to be appeased by using correct words.'" Martin challenges both perspectives. Brimstone and Treacle was remade as a theatrical feature in 1982 with Elliot and Sting.