It's late in the evening of Monday, June 5, 1944. You're a young American, 18, 19, 20 years old. You're in England, maybe by choice, probably not.

You're a sailor in the Navy, on a destroyer, a battleship, a cruiser—crossing a few miles of pitching sea toward a rendezvous with destiny. All around you is the greatest fleet ever assembled. Anywhere. Ever. It'd be a magnificent sight if you could see it, but of course you can't. All the ships are running blacked out. Don't you know there's a war on?

You're a soldier in the Army, packed aboard a landing ship with what seems like all your gear and half of somebody else's. It's raining like hell, been raining for weeks, been raining since you got to England. You're soaked, you're cold, you're seasick.

You're a paratrooper, checking your equipment for the hundredth time, wondering if there's anything more you can possibly bring that might give you the edge, waiting for your officers to tell you it's time to climb into the planes you'll be jumping out of in a few hours. You've jumped before—you had to do it five times just to earn those boots on your feet and those wings on your chest—but this time will be diffferent. This time you'll be falling toward people who want to kill you.

You're an airman, maybe a fighter pilot, maybe a member of a bomber crew. Flying over Hitler's Fortress Europe is nothing new for you, but the mission you're gearing up for now IS different. You're not going to Berlin or Regensburg or Schweinfurt in the morning. You're just going across the Channel to knock on the fortress door... hard.

You're a Coast Guardsman at the helm of a landing craft, risking your neck for the war effort just like all these guys from the more famous services. Most members of later generations won't even realize you were here. They'll assume the Coast Guard was back home, patrolling U.S. territorial waters for U-boats and living the good life on shore. They won't remember you and the hundreds of your brothers, some of whom got blown out of the water trying to get the men to the beach, until some better-informed person reminds them.

Maybe you're not an American at all. Maybe you're an Englishman, heading back across the Channel, itching to get a piece of Jerry and get some of your own back for the humiliation of Dunkirk. Maybe you're a Canadian, or an Australian, or a New Zealander, ready to fight for King and Empire. Maybe you're a Frenchman, or a Pole, or a Czech, hungry for an even more personal revenge against the men who took away your country earlier in the decade.

Whoever you are, you have a piece of paper in your pocket, and written on it are the words of the one man who controls more military force than any other single commander in history—a man who knows that his name is at the bottom of the sheet, but at the end of the day, it's your shoulders on which the fate of the world rests.

It says:

Good luck, soldier.

In the morning, you and your buddies are going to save the world.