The Currents of Space is a 1952 novel by science fiction author Isaac Asimov. It is the second book in Asimov's Empire Series. The action takes place during the time when Trantor was building a confederation of planets that would ultimately grow into the Galactic Empire.
In this story, that ocurrs around year 34500, Trantor dominates almost half of the galaxy (Earth is hardly remembered); one of its few opposition groups is lead by Sark, a planet ruled by the Nobles, who base their wealth on kyrt , a strange mineral that's only produced in Florina , planet that is of course controlled by the rich men of Sark.
The main topic of the novel is the possible destruction of Florina, predicted by Rik, a space analist whose mind has been manipulated and forced to forget this vital information. The story begins when Rik starts remembering the past and produces a break in the political situation of Sark, Florina and Trantor.