This fine but old book of Clarke tells us, this time, about political tensions between Earth and The Federation, which is a coalition of Mars, Venus and a few moons of he outer gas giants. The tension is caused by the need of the federation for heavy elements (Titanium, Uranium etc.) and by the fact that Earth is extremely rich in such elements, and the other planets aren't, but Earth is refusing to let them open mines on its surface, with the excuse that Earth itself is overpopulated and needs all of them. Eventually, it escalates into a minor war that is limited to a single battle. But most of the story is about the main hero, Bertram Saddler, who is sent by an Earth unpopular company to find a spy who was leaking information about development of military technology to the Federation, through an observatory on the moon. As Saddler is getting himself familiar with the new and hostile enviroment on the Moon, the Earth and Federation are preparing to break each other's neck.
This report prepared by Dimitri Melamoud