Great third and last book in the Mars trilogy. A lot of book to read but it is well worth it and ties up everything, well almost everything. There is a threat to Mars in terms of Earth immigration because of overpopulation and environmental disasters. The First Hundred, those that landed on Mars to colonize it, are living to be over 200 years old because of longevity treatments. They organize to set up their own government by writing their own constitution and trying not to repeat the mistakes of Earth. They do come up with something different and it works for them. The book also continues about some of the First Hundred and what problems they go through as they age. There are other things dealt with and it wrapped up to be a good book. There are times it gets sidetracked with some scientific things in great detail, but that's part of the story.
