In Hands Down: A Dick Francis Novel (Crooked Lane, Nov.), Francis continues his father’s series of crime thrillers set in the world of British horse racing.

What led to your father stopping his series?

The worst-kept secret in publishing was that my mother and father had worked on these books together. In 1999, they decided that they were going to retire. They went to Ascot, as always, to deliver a copy of their latest book to the Queen Mother in the Royal Box. Before my father could tell the Queen Mother that this would be the last book, the Queen Mother said, “I’m so looking forward to my book next year.” And I remember driving my parents home, and there was a deep depression in the car because my father and mother were saying, “Oh, God, we’re going to have to do another one.”

How did you end up taking over?

When I went to collect their new manuscript to bring to the publisher, it was only two-thirds written. And there was just a week to go before the deadline. So I literally sat down at a table and finished it for them. I’d been discussing the plot with them, so I knew I could do it. They announced their retirement, gave the Queen Mother the last one, and my mother died of a heart attack soon afterwards. So Dad said, “Right, no more books.” And everyone thought that was the end of the Dick Francis novels. Five years later, my father’s literary agent asked for permission to ask an existing crime writer to write a new one. I said, “Well, before you ask anyone else, I would like to have a go.”

What made you think you could pull it off?

I’ve been involved in writing bits of Dick Francis books for all my life. I wrote all the scientific bits of Twice Shy. I wrote the computer program in it, which was very cutting-edge at the time, but now is an embarrassment.

Your father’s series started in the 1960s; have things changed in horse-racing since then to make plotting more difficult?

Yes. So much more difficult. One of his earliest books was about kidnaping stallions. Well, you just couldn’t do that today because all horses are DNA-tested and microchipped. Those technologies mean that it’s almost impossible to run a ringer. There are certain things I’d written in books which now wouldn’t happen. In fact, one or two things have been closed off by the authorities after I’d written about them, like smuggling drugs from South America inside horses. Horses now are routinely x-rayed to ensure they haven’t got things inside them.