...and we have a winner!

Thanks, everyone who responded! We are surprised that we have a winner so quickly. The answer may surprise you.

Congratulations go to Dave Kreiseder for being the first person to respond with the correct answer.

...and the answer we were looking for is:

"Gothic Serpent"

That was the name of the specific operation for which "Irene" was the go word.

Thanks for playing! And don't worry, we will do this again. We have lots of great prizes, so stay tuned for more.