The YA author and former Children's Laureate told the audience at the Hay Festival that when she thinks the series is complete she is drawn back to writing another book encouraged on by her lead characters.
Blackman, who also writes television drama, said she was thrilled to write the Dr Who episode featuring the Sixties civil-rights campaigner Rosa Parks. She said although Dr Who is fiction she tried to accurately portray Parks and that she enjoyed mixing history and science fiction genres.
Her father encouraged her to read factual books, but was not a fan of fiction, so she went to the local library to borrow works of fiction. She said, "I wouldn't be sitting here if it was not for the local library."
She developed a passion for Shakespeare at school after initially dismissing him, and happily admits to drawing inspiration from some of his great plays. Some of the storylines in her books have become oddly prescient pre-dating changes and events in society.
If you are interested in young Adult Fiction you may like to see Geek Girl author Holly Smale in conversation with Laura Dockrill on Wednesday at 2.30pm. If you like watching Hay Festival events digitally please sign up to the Hay Player