The world is falling, and there is a race against time and a “monster” in the sky that’s coming to devour the world.
The engineers try as hard as they can to save the world, but the most they have been able to do is delay the inevitable. After a few years our narrator then becomes an engineer and works to make the world safe, even while trying to escape the clutches of the solar system devouring monster.
This world works on points allotted to everyone, based on which they can live and work in particular rings. It’s not a very pleasant way to organize a society, but people have accepted it. And just like humanity in general, here too there is a streak of happy abandon, even while being acutely aware of the grave possibilities.
There are secrets, classified information, and terrible choices for people to make, and the narrator makes their own choice at the end.