The sun went out. No one's really sure how it happened. It was unexpected - even our scientists and scholars didn't see it coming. But it did. The world became shrouded in darkness. At first there was panic, confusion, riots. The police quickly took control of the situation and waited for news from the president. Electricity was still functional, and thus, we still had the glimmer of lights in the dark. The president began work on a massive project called Undercity One. No one but those working on it knew what it was until it had been completed.
Built underground, Undercity One was a huge sprawling city with UV lights to simulate a real sun. After Undercity One, the production of Undercity Two went underway. Pretty soon, the 114 Undercities had been completed. People were packed in the small cities, but it felt like home. The sunlight still streamed down on them, there were still shopping centers and beaches and malls. Everything was the same for those who lived underground.
But there were those who refused. The government let them be, of course. The Darkwalkers. The Darkwalkers preferred the old cities - now abandoned and ruined - to the Undercities. "While it may feel like home, we're leaving all we worked for behind." Darkwalkers were scavengers, finding food where they could, living where they could. Most lived in large "Torch-Cities", old towns that were walled up and strung with lights of all kinds.
But the Darkwalkers faced a serious problem. While at first it seemed like it was just a small, unexplainable occurrence, people began to die, violently and suddenly. The Darkwalkers quickly found the source: a mysterious fog that persisted even when it shouldn't. No rain was about, and still the fog crept along the streets, repelled only by light. It would consume the Darkwalkers and kill them from the inside out. It was a peculiar enemy that no one knew how to kill.
Now, the Darkwalkers live in a fragile state of safety - it's only a matter of time until the batteries in your flashlight run out. And when they do....