BuzzFeed has released a fascinating new video outlining the “greatest act of deception” during World War II.

The secret operation, reportedly called “Operation Mincemeat,” involved the British government taking a corpse from a London morgue, dressing it as a drowned soldier and planting it on a beach in Spain for the enemy to discover. The entire plot, carried out 1943, was designed to deceive the Germans.

We won’t give away the whole story as BuzzFeed actually does a great job telling the unbelievable tale.