Grimsby-born Alex Gerlis was a BBC News journalist for nearly 30 years and is the author of 11 factually-based WW2 spy thrillers (with lots of Lincolnshire action). His best-selling The Best of Our Spies is currently being developed for TV. When asked if he was ever in the intelligence services he declines to answer … Though he now lives in London, he remains a supporter of Grimsby Town, which helps him cope with the highs and lows of writing.

Neil R Storey is an internationally recognised expert on the darker aspects of British history, often appearing as a guest expert on TV and radio. His latest book, Nazi Spies and Collaborators in Britain, 1939-1945, uses recently released documents to explore how German agents penetrated our borders, how they were recruited and operated and who was ‘likely to assist the enemy’ in the event of invasion.