Actor Kit Harington, who both devised and stars in the new TV adaptation of the Gunpowder Plot (Saturdays, from 21 October), says he is surprised that the familiar story of what happened at the Houses of Parliament on 5 November 1605 has been so little dramatised. Jimmy McGovern wrote a two-parter for BBC2 in 2004 and three years ago there was a docudrama, also on BBC2, in seventeenth-century language: but surely, Harington mused, such an important historical event deserved a blockbuster series on BBC1?