Like all the Allied bombers of World War II, the crew of the Lancaster ME669 had one of the most dangerous jobs in the Air Force: to dodge deadly enemy fire and drop mega-tonnes of high-powered explosives over Nazi Germany. Without them, Hitler may have emerged victorious. But the tactic called "total war", a controversial strategy that turned cities into legitimate targets, overshadowed their legacy. Yet, for the more than one hundred thousand volunteers - half of who would not return - there was no other option.