After the flood-parkour city

There are only three rules: Never stay on the ground. Never trust an empty building. And when the drones start flying in formation—RUN. Because something has started controlling them. Decades ago, the world's glaciers melted, sending enormous waves across the planet. Entire cities disappeared beneath the ocean. The few skyscrapers that remained became isolated islands, connected by broken bridges, rooftops, cranes, and improvised zip-lines. The surviving population split into gangs, settlements, and lone survivors. The streets are gone. The rooftops are the new streets. People sprint across collapsing buildings, leap between skyscrapers, climb radio towers, swing from cables, and use boats to cross the deeper sections of the city. Every rooftop can become a battlefield—or a place to find food, equipment, and other survivors. Before the flood, automated security drones were deployed throughout the city. When civilization collapsed, many of them continued following their old programming. Some patrol the skies. Some protect abandoned corporate buildings. Some hunt anything they identify as a threat. Survivors have learned to hide from them, outrun them, or salvage their technology. Nature has begun reclaiming everything. Trees grow through apartment buildings. Vines cover skyscrapers. Entire rooftops have become forests. Fish swim through submerged shopping centers, while strange animals have adapted to the flooded environment. Below the surface are sunken subway systems, military bunkers, laboratories, shopping malls, and entire neighborhoods nobody has explored for years. And some survivors say they're hearing machines moving beneath the water.