From the incredible Great Sky River, this book continues the story of Killeen, now a leader who must get his people to the promised spot, though he still doesn't quite know why. They are on an old human ship that was unearthed and allowed to take off in the last novel, heading to the center of the galaxy. Along the way, they encounter an insect-like race that has much more in common with mankind than meets the eye.
This book is full of scientific detail that I followed more or less. As other reviewers note, it contains a cosmic string that has been harnessed by the insectoids to harvest the resources of entire planets. Their common enemy is the machine intelligences, which have a vast web of outposts throughout the galaxy, tolerating organics at best, hunting them brutally at worst.
There is no doubt that this is fun, but unfortunately I couldn't leave behind my sense that someone was making this up - I couldn't suspend my disbelief, which I most definitely could in the previous volumes. In spite of many interesting character developments, there is a rushed feeling to this book, as if the concepts are beginning to be more important than the plot. The characters seemed more flimsy, easier to label, and the story line obscure and simply strange. I was barely able to finish this and the subsequent 2 novels, where it is all supposed to come together, were only skim books from which I wanted to find what happened without any particular magic or felling that belonged exclusively to this as, for want of a better term, a work of art.
REcommended, but only for those invested in the series.