Penny Smith does a weekly book club on her show every Saturday.
Every week, she invites an author on to talk about their work, their techniques, and how the story developed.
Last Saturday, Broadcaster Simon Mayo entered the club, talking about his book Blame, where a teenage girl and her family are imprisoned for crimes their relatives have committed.
He revealed the novel's origins.
"It started off as an adult book," he told Penny, "When the blame story came along, I didn't know where it was going to fit.
"Originally, the parents were supposed to be the lead.
"Then I swapped the lead around to make it the teenage girl, and then it becomes a young adult book."