TNA Podcast: Hunting for Spies in The National Archives

From an entertaining lecture given on 15 January, Times journalist Ben Macintyre talks about his latest book Double Cross: The True Story of the D-Day Spies (Bloomsbury, 2012).
He emphasizes the importance of meticulous record keeping in managing double agents in the lead up to the D-Day invasion, adding imaginatively to Churchill's rhetoric

"We shall fight on the beaches, we shall fight on the landing grounds, we shall fight in the fields and in the streets, we shall fight in the hills" 

the line

We shall fight them amongst the filing cabinets.

http://media.nationalarchives.gov.uk/index.php/hunting-for-spies-in-the-national-archives/