Arrangements for deploying double agents into occupied territory remained buried in the Security Service files, hiding the cost of moving assets from safehouses to the front lines.
Kept hidden in the Security Service's personal files, the transit of a fake commercial representative from Lisbon to London provided the cover for a strategic deception that saved thousands of lives.
A journalist in occupied Paris played a lethal game of shadow-boxing with German intelligence, using a radio link to feed the Reich lies until the city was liberated.
Strategic deception for D-Day relied on a fictional spy network that Thomas Harris had to protect through ingenious contingency plans as Abwehr defections risked exposing Juan Pujol García.
Nazi high command believed a phantom army existed in Britain during D-Day, but the ingenious plans used to shield this lie from exposure stay hidden in the archives.