How US sailors pulled off a daring high-seas mission to save a sinking Nazi submarine and capture its secrets

[Tony]

In early June 1944, more than 100,000 Allied soldiers and thousands of ships and aircraft massed on the English coast, preparing for one of the most important battles in history: the invasion of Normandy.

Several hundred miles to the south, the six ships of US Navy Task Group 22.3 were on a rather routine U-boat hunter-killer patrol — a mundane mission in comparison.

After a few weeks at sea, the task force was heading to Casablanca to refuel. On the way, they pulled off one of the most impressive naval feats of the war: capturing the German U-boat U-505 completely intact — including its valuable Enigma machines and the codebooks needed to use them.