Stranger than fiction MI5 tales revealed in first National Archives collaboration

From Guy Burgess’s briefcase to microdots secreted in talc, an exhibition reveals remarkable items from the agency’s archives – and the extraordinary stories behind themThe agency that would become MI5, originally known as the Secret Service Bureau, employed just 17 staff in 1914; by the end of the first world war, the number working for Britain’s domestic counter-intelligence agency had swelled to 850, including a number of female administrators.While valuable for managi