The world after global warming. Humanity has taken refuge in three gigantic underwater cities at the bottom of the ocean.
Those who are expelled from the cities, for lack of space, barely survive on the burned lands. Meanwhile, the megacities exchange millions of containers loaded with goods every day.
At the command of ultra-fast boats, a few inhabitants of the underwater cities started stealing these precious containers, in order to deliver them to the banished.
Some are more successful than others.