MI6 used bodily fluids for invisible ink!

There’s a new book out all about the British Secret Service at the start of the last century until the end of World War II.

The author had access to their files and some of it’s amazing.

Especially the bit about them experimenting with different kinds of invisible ink during the First World War. What did they find was the most effective ink?

Semen. I know. Handy.

Rather brilliantly the discovery was written about in the diary of the deputy head of military intelligence who was called Mansfield Cumming.

Amazingly they found the contents of the man biro didn’t react to the main methods of detecting invisible ink plus of course it was pretty much readily available when out in the field. Or more likely in the bedroom. Or loo. 

Imagine that. That’d make one heck of a Bond movie.

“James! What on earth are you doing on my desk?”

“Sorry, just refilling my pen"

"Shaken not stirred?"