The City Must Survive.
New London has survived the end of the world, multiple times over. It's been years, decades, with more and more people coming to the city. Survivors concentrating as, one by one, their old homes fail, their resources run out, their plans crumble, and they all make their way to New London. The last true city in the world, for all that twenty-five thousand some souls would be pathetically small for a city in the old one.
The city grows. Sprawls. Housing districts and hothouses spread forth, drawing out what fertility they can from the overtaxed soil. Great grinding wheels strip the ground bare of coal, every day seeking deeper, gathering crumbs from crevices. The places that once were forests of this land shaved clean, frozen trees processed into material, and entire mountains of iron ore steadily stripped bare to provide for the ever-hungering maw of the city.
At the heart of it all, the Generator, an ever-burning, ever-beating heart. An open maw, devouring coal by the ton and returning it as life-giving steam, the blood of the city. The weather never truly lets up, and exploration out of the Frostlands remains nigh impossible, but for decades, after dozens of improvements and refinements and rebuilds, the Generator yet burns on, protecting New London from cold, privation, chaos.
But the Great Frost never lets up. The accursed storms always return, once in a while, walls of white fury blotting out the sun and blasting winds chill enough to freeze alcohol solid through the city streets. People huddle inside while the storm rages, most work shuts down and New London lives off its fat. Great stockpiles of goods, coal, food, materials are steadily drawn down to maintain the Generator, its steam-pipe arteries, and the buildings of the City through the weeks-long storms...
Every one is a crisis. Every one, they have not been sure they would see the other side of. And this one is different...
When the winds die down and the snow stops falling, they thought it was merely night at first. The moon and stars blotted out by thick clouds above. The City merely went about its business, clearing snow, re-opening factories, getting back to work.
But at the edges of the city, the logistics stations that connect it to the outposts and colonies, instead of railway tracks and telegraph wires leading off into the icy distance, there is...
Ocean. Dark water, not even especially chill, extending beyond the horizon.
Needless to say, this is confusing and alarming.