Simon Guerrier has written countless Doctor Who books, comics, audio plays, and documentaries. As research for one of his Doctor Who stories, he took night classes in astronomy at the Royal Observatory Greenwich which resulted in an A-plus and the plot for another Doctor Who story. Simon regularly writes for Horrible Histories magazine and the medical journal The Lancet Psychiatry. With his brother Thomas, Simon also makes films and documentaries most recently The Fundamentalist Queen, about the wife of Oliver Cromwell, broadcast by the BBC in December 2014.