PW: How does your second posthumous collaboration with Dorothy Sayers, A Presumption of Death, differ from your first?

Jill Paton Walsh: With Thrones, Dominations, I was working in the dark with a plot that had been worked out. In A Presumption of Death, all I had to use were propaganda letters, and so I had a completely free hand with the plot. The characters then became the difficulty, because this time they needed to be moved into a situation which was so different from when we last saw them in her hands.

PW: Which was in 1936?

JPW: Yes. Four years later, in the early months of the Second World War, everything looked so grim and things were so scary, that I can't really imagine Lord Peter and Harriet behaving as they did, as insouciant newlyweds, dizzy with happiness. This time, the characters needed to be developed, not into what they had been, but into what they would have become. So there's a subjunctive in both processes; in the first case, what Sayers would have written, how she would have had the plot develop; in this one, what the characters would have been in different circumstances. I found the character difficulty rather more interesting, actually. I was very interested to crack that one.

PW: Did parallels between Harriet's life and her creator's—which you don't share—make it difficult for you to write about Harriet?

JPW: It's Harriet into whose skin I can most easily get. I'm afraid I've been relatively lucky with men. Sayers did have a terrible love affair, and Lord Peter is, in many ways, the man she wished she had met. Sayers put herself into her own books in the form of Harriet, but she didn't exactly promote Harriet, who is not, by any means, an idealized character. Just compare her with Peter. Look how grumpy she is, how bad-tempered, how sometimes cool she is. She's not beautiful, and has a hard, chilly-eyed view of life. And that's what gives her this convincing quality.

PW: Would you consider writing an entirely original Wimsey-Vane mystery?

JPW: I would be fascinated, but I would be increasingly careful. Each step you take away from an authentic piece of work, the harder it's going to be to maintain authenticity, and I would need to think really hard. I mean Lord Peter and Harriet are lovely fun, they're awfully entertaining to write about, and I can think of loads of books about them that I would love to write—that's not the problem. I would need to be sure I could do it well. And by well, I mean really consistent with Sayers's work.

PW: Would you consider writing a book in the Sayers style without Lord Peter and Harriet?

JPW: I would be much less interested, because what does fascinate me is this sort of sparkly, witty, loving dialogue between the two of them in which the detection takes place—I do find that extremely engaging.

PW: How would you answer criticism that Lord Peter in A Presumption of Death isn't the same as Sayers's Lord Peter?

JPW: I'm fairly certain that more Lord Peter in 1940 is not more of the same Lord Peter. It couldn't be. If someone said you've abused him, you've dumbed him down, he's not as funny as he used to be, I'd respond, this man is 50, his country is threatened by fascism, America's still in the grips of the Neutrality Act, and it looks like we're going to lose. I'd defend the changes in character as natural developments in the changed situation. If the situation lightens again, then you'd have to work out whether he would go back to being the old frivolous Lord Peter. I don't know the answer, really. I'd like to find out.