The whole world was dying but still everyone made time for one last war. The Disease had entered its tenth year and the war had entered its fifth and there didn’t seem to be any cure in sight for either of them. Some people said that because of the nature of The Disease, the older generation, seeing that their end was finally near, decided to settle all the old scores. One final global bar fight before last call.

      The world had already lost twenty percent of its population by the time Tommy and I began our trip. The Disease took the old—killing some, simply putting others into a long, soft slumber—and the war took the young and everyone else tried to lose themselves in whatever they could: drugs, alcohol, sex, science, art, poetry. Everyone had impetus and direction now that everything was falling apart.

      When it all first began, Tommy and I were too young for the war and far too young for The Disease, so we only walked in the shadow of it all, watching and waiting for our turn. Our parents were already dead and we didn’t have any other family. We’d never live long enough to catch The Disease, so we viewed it with a detached interest and sympathy.

      The Disease started in Russia, but because Russia tends to be tight-lipped about what happens within its borders, it’s been difficult for anyone to say just how long it had been happening before the rest of the world found out about it. The UK was the first country beyond Russia to notice the outbreak. It began in a retirement home in London where one morning the staff went to their patients’ rooms to find all of them asleep and unable to be awakened. Within hours there were reports coming in from other countries about the extremely elderly falling asleep and never waking.

      The Disease garnered a lot of different names in those first frightening weeks: The Lullaby, The Long Goodnight, Sundowners Disease. The last one was meant to make fun of the elderly. After all, those at the end of life were expected to pass away eventually. So for a while, the world was concerned, but not alarmed. It wasn’t until The Disease had been quietly shutting the doors on the oldest of the population that someone at the CDC noticed a decline in the average age of The Disease’s victims. Something that began affecting only those in their midnineties and above had progressed to affect those about five years younger. Then the world watched as, over the next couple of years, the average age was reduced even further.

      The Disease was coming for everyone. It would begin by emptying out the nursing homes, then progress to the retirement villages, then on and on until, eventually, it would hollow out the office buildings, the nightclubs the youth had once filled with reverie until, one day, there would be no one alive old enough to reproduce. Not long after that, whatever children left would turn out the lights on humanity by drifting off into one long, peaceful slumber.

      The world would not end with a bang or a whimper, but in a restful sigh.

      Staring down the barrel of that future was what sparked the war. As people panicked they began to blame others. And that blaming donned a coat of nationalism. Russia was the primary target in the beginning since that was where The Disease had begun. Before long, the war spilled over from its borders and into the rest of the world.

      Now, five years later, America was the last uninvaded country on the planet. But that wouldn’t last. The average age of victims of The Disease had reached sixty—the age of most politicians and military officials. The war was losing its direction and ambling on the shaky legs of enlisted men and women who didn’t see any point in fighting when there was a disease coming for them. So the government turned back to the draft.

      The Disease was too far away for seventeen-year-olds to really understand or fear. Youth has always been a haven for invincibility, and this was no different. The papers from the draft board went out, scooping up boys and girls in its bloody hands. And one after another they went, they died, and the world grew a little lonelier.

      Though it all felt far away from me and Tommy, I knew, of course, that it couldn’t last.

      Our parents had been dreamers. Our mother was a teacher and believer in things magical, like newspaper horoscopes and the ability of whispered fears to manifest in a person’s life. Our father believed in magic of a different kind. He was a writer and, sometimes, amateur astronomer. His magic was a distant moon named Europa.

      He fell in love with it at an early age and then passed that love on to my brother and me. He could never know where his obsession with a small ice rock located over three hundred million miles away would lead his children. Like the stars led our father, the memory of our father led my brother and me.

      For me, our journey started before I was even born, in letters my father wrote to me and my brother. For Tommy, it all started with a letter from the Draft Board.

      For three hard days my brother failed to