The life saving deck of cards. I mean literally!
“During World War II, the United States Playing Card Company joined forces with American and British intelligence agencies to create a very special deck of cards. This deck was specifically created to help Allied prisoners of war escape from German POW camps.”
“This deck of cards became known as the “map deck.” It was made by hiding maps of top-secret escape routes between the two paper layers that make up all modern playing cards.”
more info at: bicyclecards.com and telegraph.co.uk
