In this world we find that the Mars colonies are kicking ass while Earth has become a crime ridden totalitarian hell hole.

A martian colonist is called to Earth in order to claim an inheritance from his uncle. The colonist soon learns that there is a permanent curfew imposed on humanity which is enforced by robotic rats and flying devil rays which kill anyone out past curfew.

The uncle is a bit weird and, in order to get the prize treasure in his inheritance, he needs to visit a friend at night. In order to do this he needs to get a pass from the police. They give him a broadcasting device that will keep the robotic patrol bots away from him 6 hours.

There are a couple of holes that I see. First off, there really isn't any adequately explained reason why he actually needed to travel at night other than that it was necessary to show the reader the dangers of travelling at night.

Nevertheless, it's a fun tale of an irritating colonist giving the finger to the local cops.


SPOILER

The final quote is pretty good.

You people have already had your chance ... and you threw it away. ... This is no universe for the meek and frightened. And anybody who surrendered the night with as little fuss as you Earth-siders did, just can't amount to very much. You can't see the stars in the daytime.