This was a rather weird story about humankind. I would describe the genre as a mashup of "Victorian Future Apocalypse". The society is Victorian while the setting is very obviously in the future. Basically it is one big metaphor ... I had some trouble getting into the story at the beginning. Mankind left Earth and returned much later. They built themselves 9 castles and lived there as Gentlemen and Ladies, in decadence, served by the races of the Meks, the Peasants, the Phanes and the Birds. But then the Meks revolt. Obviously feeding them the "Syrup" was not enough.

It's a good story, I just did not find the process of reading it quite as enjoyable as I had hoped from my previous experience with Vance's writing.