I wished that Reynolds' last book was five times longer. This book certainly was very long, possibly that much longer! It was epic spacer with a small cast of characters learning about the millions of civilizations that came before them, and what happened to them. There’s a lot of traveling around, some deep sleep, some xenomorphic mysteries and a lot of 'splainy little passages in-between. I appreciated that Reynolds has a big vocabulary and knows a lot of stuff. However occasional parts of this book seemed to be just to talk about, for example, black hole theory and not to advance to plot. As a result, it was a little plodding plot-wise but really well-written