For the first time ever, an artist has been invited into MI6, for an unprecedented behind-the-scenes look at Britain's Secret Intelligence Service.   To mark MI6's 100th anniversary, James Hart Dyke spent a year shadowing spies and illustrating their activities.   It was a top secret mission; he was required to sign the Official Secrets Act, and was allowed to tell only his wife and parents what he was doing.

His challenge was to capture the mystery, intrigue and excitement of the world of espionage, without letting any state secrets slip.  MI6 gave him extraordinary access.  But Hart Dyke's work was eventually censored; some drawings and paintings even have holes cut out of them.

Hart Dyke's work looks pretty ordinary at first glance.  If you walked in off the street, you might think his art portrayed everyday images like a man in a hotel room, a woman standing on a street corner or a neighborhood in a third world country.   But  we reveal the "real life of a spy" - and show how, when it comes to the murky world of espionage, nothing is ever as it seems.

In this episode of "The Revealer", James Hart Dyke talks about how the project took over his life, and the biggest challenge he faced on the job.