What, then, does detective fiction say about her? ‘That I am a woman who likes life to be ordered. In a long life, I have never taken a drug or got drunk, and I say that not as a matter of pride: it’s because the idea of being out of control is appalling to me. I think that when one writes detective stories one is imposing order, and a form of imperfect but human justice, on chaos.’ In fact, as with the later work of her hero Dorothy L Sayers, a great deal of the fascination of James’s detective fiction lies in the way chaos flourishes in the midst of the novels’ rigid structure – the internal psychological mess that brings about murder. ‘I think there’s been a huge change since the novels of the Golden Age,’ she suggests. ‘What was popular then was the puzzle: such qualities as psychological truth or even atmospheric location were secondary to it. For me, characterisation is at the heart of my books. From the start, I felt that what I was doing was examining human beings under the strain of an investigation for murder. And such an investigation tears down all the walls of privacy that we build round ourselves and reveals us for who we are. It’s a fascinating way of dealing with people.’

the great P. D. James, who has just died at age 94. R.I.P.