“You’re probably wondering what happened before you got here. An awful lot of stuff, actually. Once we evolved into humans, things got pretty interesting. We figured out how to grow food and domesticate animals so we didn’t have to spend all of our time hunting. Our tribes got much bigger, and we spread across the entire planet like an unstoppable virus. Then, after fighting a bunch of wars with each other over land, resources, and our made-up gods, we eventually got all of our tribes organized into a ‘global civilization.’ But, honestly, it wasn’t all that organized,or civilized, and we continued to fight a lot of wars with each other. But we also figured out how to do science, which helped us develop technology. For a bunch of hairless apes, we’ve actually managed to invent some pretty incredible things. Computers. Medicine. Lasers. Microwave ovens. Artificial hearts. Atomic bombs. We even sent a few guys to the moon and brought them back. We also created a global communications network that lets us all talk to each other, all around the world, all the time. Pretty impressive, right?

“But that’s where the bad news comes in. Our global civilization came at a huge cost. We needed a whole bunch of energy to build it, and we got that energy by burning fossil fuels, which came from dead plants and animals buried deep in the ground. We used up most of this fuel before you got here, and now it's pretty much all gone. This means that we no longer have enough energy to keep our civilization running like it was before. So we’ve had to cut back. Big-time. We call this the Global Energy Crisis, and it’s been going on for a while now.

“Also, it turns out that burning all of those fossil fuels had some nasty side effects, like raising the temperature of our planet and screwing up the environment. So now the polar ice caps are melting, sea levels are rising, and the weather is all messed up. Plants and animals are dying off in record numbers, and lots of people are starving and homeless. And we’re still fighting wars with each other, mostly over the few resources we have left.

We lived in the Portland Avenue Stacks, a sprawling hive of discolored tin shoeboxes rusting on the shores of I-40, just west of Oklahoma City’s decaying skyscraper core. It was a collection of over five hundred individual stacks, all connected to each other by a makeshift network of recycled pipes, girders, support beams, and footbridges. The spires of a dozen ancient construction cranes (used to do the actual stacking) were positioned around the stacks’ ever-expanding outer perimeter.

The top level or “roof” of the stacks was blanketed with a patchwork array of old solar panels that provided supplemental power to the units below. A bundle of hoses and corrugated tubing snaked up and down the side of each stack, supplying water to each trailer and carrying away sewage (luxuries not available in some of the other stacks scattered around the city). Very little sunlight made it to the bottom level (known as the "floor"). The dark, narrow strips of ground between the stacks were clogged with the skeletons of abandoned cars and trucks, their gas tanks emptied and their exit routes blocked off long ago.

But after the oil crash and the onset of the energy crisis, large cities had been flooded with refugees from surrounding suburban and rural areas, resulting in a massive urban housing shortage. Real estate within walking distance of a big city became far too valuable to waste on a flat plane of mobile homes, so someone had cooked up the brilliant idea of, as Mr. Miller put it, “stacking the sumbitches,” to maximize the use of ground space. The idea caught on in a big way, and trailer parks across the country had quickly evolved into “stacks” like this one—strange hybrids of shantytowns, squatter settlements, and refugee camps. They were now scattered around the outskirts of most major cities, each one overflowing with uprooted rednecks like my parents, who— desperate for work, food, electricity, and reliable OASIS access—had fled their dying small towns and had used the last of their gasoline (or their beasts of burden) to haul their families, RVs, and trailer homes to the nearest metropolis

I slipped out the window as quietly as possible and, clutching the bottom of the window frame, slid down the cold surface of the trailer’s metal siding. The steel platform on which the trailer rested was only slightly wider and longer than the trailer itself, leaving a ledge about a foot and a half wide all the way around. I carefully lowered myself until my feet rested on this ledge, then reached up to close the window behind me. I grabbed hold of a rope I’d strung there at waist level to serve as a handhold and began to sidestep along the ledge to the corner of the platform. From there I was able to descend the ladderlike frame of the scaffolding. I almost always took this route when leaving or returning to my aunt’s trailer. A rickety metal staircase was bolted to the side of the stack, but it shook and knocked against the scaffolding, so I couldn’t use it without announcing my presence. Bad news. In the stacks, it was best to avoid being heard or seen, whenever possible. There were often dangerous and desperate people about—the sort who would rob you, rape you, and then sell your organs on the black market.