There is no night in the Everburning City. There can never be.
Hundreds of years ago, a deadly, unnatural fog swept across the world. Advancing across countries in a matter of years, the mist killed everything it covered. Only tall mountains rose above what refugees named the Gloam, and the widest rivers did not bar its path.
Only fire could halt its march. But as other strongholds before the City discovered, no fire on earth could burn forever. The Gloam was relentless, intractable, and, as far as the multitudes driven to the furthest corners of the world were concerned, eternal.
As the Gloam swallowed the world, a mad gamble was commissioned at a bend of a wide river. The Crafters; people both gifted and cursed with a will that can command the flame, attempted to reach a fire that could outlast the besieging mists of the Gloam. The audacity of desperation inspired a hundred crafters to burn a hole down through the miles of rock into the fires beneath the earth.
The wound that the Crafters inflicted upon the world is known as The Bore, and its fires have held the Gloam at bay for four hundred years, even as the City expanded to house and feed millions.
The City harbours its denizens by the fires of the abyss, and the blood of its heroes.