The novelist shifts to nonfiction with Parallel Lives, an account of the Cold War courtship of British art historian Francis Haskell and Soviet curator Larissa Salmina.

How did Parallel Lives evolve from a series of conversations you were having with Larissa into a book?

It took quite a long time, because it was just about keeping her entertained while getting the story down. I went down about once a week, so it wasn’t a rushed thing. It was only after about two years when we started talking about Francis’s diaries and I started reading them—then it began to come together. I began to think of how you could make a story out of the very different, separate accounts of the lives of two people who don’t actually meet until they’re 35.

What was it like going back into nonfiction mode?

Well, it was quite curious, really, because it’s such a long time since I’d done anything like that. I mean, I wrote a book on art history in 1988. I’ve done a few things since then, articles and whatnot. And this book is not particularly scholarly. Even so, I put in footnotes, and I had to check that the quotes were right. And that was all very dull and infuriating, because I was completely out of the habit of taking notes. I mean, I can scarcely write anymore, so I simply went into the National Gallery archives and just snapped everything with my camera rather than writing it down. I had these great quotes, but I had to go back and find the damn things. But it’s quite good discipline to remember how to do this stuff. Occasionally, I was very glad that I was a novelist and that at a pinch I could always just make stuff up. Larissa always wanted me to make stuff up, but there wasn’t any real need to. The story itself was so bizarre that it didn’t really need any input from me at all. She wanted me to make her a spy, you see, because quite a lot of people in England thought she was a plant by the KGB. I asked her, and she said, “No, I wasn’t a spy. I would have loved to have been a spy, but nobody asked me.” Then she said, “Why don’t you make me a spy anyway? That’d be much more interesting.” But I left that out.

Why did you choose to end the narrative with their marriage?

One of the great troubles with biographies is that a lot of biographical subjects do one interesting thing, and the rest is a fairly ordinary life. With these two, after they got married, that was it, really. It was a very happy life. The bit I write about was, in many ways, the unhappy part of their life, but it was much, much more interesting. Their marriage was a natural conclusion to the story, because that’s when she left Russia and he managed to turn himself into a human being, rather than the rather miserable character he was before.