Operation Mincemeat is the true story of Ewen Montagu's book, based on the plot he helped to create, along with Charles Cholmondeley and...wait for it...Ian Fleming. Yes, that Ian Fleming, who really was a higher up during WWII.
The author could have livened up the prose a bit, it's a large book and extremely dry in many parts, and honestly if I wasn't so interested in the story itself I may not have finished it. But the history behind fooling every Nazi from those who found Glyndwr Michael's body in supposedly neutral Spain all the way up to Hitler is an interesting one.
I recommend the movie, the BBC companion, and the book for hardcore WWII buffs. I'm sure there's a simpler version of this fascinating operation someplace.
Makes me think about plots...