When a human diplomat kills his alien counterpart by insulting him to death, and then dies in the process himself, it sparks a race against time to acquire the one object that can appease the aliens and prevent the enslavement of the entire human race. An electric blue sheep of the breed "Android's Dream". However, someone has been killing the Android's Dream sheep and now there's only one creature alive who can fit the bill and she must be kept safe at all costs.
The entire first chapter sets the tone of the book, with one of the longest and most sophisticated fart jokes I have ever read. Which is not to say that the humour in this book is entirely scatological.
The book contains political and social intrigue, pitting various local and interplanetary government departments, alien races, and science fiction religions against each other, each with their own agenda regarding the sacred sheep. John Scalzi puts together alien races that are both simple to understand while being incredibly complex. There's also some very good, and very funny action scenes.
This is my second reading of The Android's Dream, and honestly it's even better the second time around when you get to stifle a snort of laughter on the bus or train in anticipation of what is to come.