This is the ninth in a 10 novel series which was mostly written by Stephen Goldin. Doc Smith wrote a novella called Imperial Stars which Goldin expanded into the first novel, and then Goldin wrote another 9 novels in a long story arc. But Smith is the famous one, so his name appears in large letters everywhere and Goldin is barely mentioned.

The setting is a universe where a Russian Feudal system has somehow become the dominant mode of government and of the language, so we see Russian words sprinkled throughout the conversations. Humanity has spread to a number of planets with varying characteristics. One of these is DesPlaines, a high gravity planet whose inhabitants have adapted by becoming shorter and stockier, and which has developed a unique attraction, The Circus of the Galaxy. What people don't know is that this circus is also a key part of the secret service SOTE, the Service Of The Empire. This allows for an interesting twist for space opera, a series where the heroes do not have secret weapons or super powers, merely acrobatic training.

Lady A. comes to the government with deadly news. The planet Omicron has been invaded by an alien menace which is intent on wiping out the human race. She says they must join forces to confront this enemy and proposes a truce for the duration. But can she be trusted? Is this what it looks like, or just another twisted plot? But Jules and Yvette d'Alembert, top agents of SOTE, and their friend Pias Bavol, have to unravel this plot and save the Empire. The book is fast-paced and a good combination of space opera with spy thriller. But since this a 10-novel story arc, each novel builds on what went before, so do not read them out of order.