Summarizing the book won't really do it justice – there are too many inter-locking threads to the tale. The ambition of the book – tackling religion, artificial intelligence, war, exploration, God, fate, progress, discovery, gender roles – is staggering. Tchaikovsky takes a compelling premise and consistently subverts expectations – playing with notions of time, linear progress, and evolution – making the book not only enjoyable, but important. Highly recommended.