All the usual Simon R Green trademarks are here - vivid, loveable characters, great descriptive passages, really unpleasant baddies and plenty of laughs.
The book focuses on Owen Deathstalker, an aristoctact inexpicably outlawed by the empire, who is forced to recognise the empire's inhumanity and cruelty and then vows to bring justice. As well as Owen and his closest allies - Hazel, Ruby and Jack, the book contains a veritable cast of thousands and lots of other stories are pursued. It's a mark of how well the characters are drawn by the author that it never becomes confusing.
Owen's a great hero, but a lot of the best characters play smaller roles, like Finlay Campbell - a man with two identities and Captain John Silence loyal officer of the empire.
The book contains some memorable passages: for example the Empresses' cybernectic maids/bodyguards and Wormboy Hell - are the stuff of nighmares that remain vivd after reading.
It's also interesting as you read on in the series to see the way that all the little characters and plotlines do get developed.