In a future where plague has left the human race in isolated pockets without technology, a group of people go out in search of "ancient" texts and technology.

This book was certainly entertaining, but it lacked the punch I was expecting.  The beginning was quite slow, though I can see the need for it.  The expedition was eventful, but didn't show the range of artifacts that I would have liked about the "Roadmakers", nor the knowledge gain.  If this was book one of several, we could see the breadth of knowledge they acquired.  I would have also liked to see the journey home, and the reception when they got back.  Perhaps finding out what happened to the original cataloguers would be nice, as well.  That's quite a wish list!  But I did enjoy the book.  The ending just seemed like a cheat -like writing at the end of a movie telling what happens to the characters.  It also seemed like a cheat that they didn't have to deal with their decision to destroy the AI -the trains home would be deactivated, too!  That leaves future explorers without the transportation that took these guys half the distance they traveled.