It is a sociological story of urban class warfare and political intrigue, taking place in the fictional South American capital city of Vados. It explores the idea of subliminal messages as political tools, and it is notable for having the structure of the famous 1892 chess game between Wilhelm Steinitz and Mikhail Chigorin. The structure is not coincidental, and plays an important part in the story.

Nominated for Hugo Award for Best Novel in 1966.