Asymptotic is the word that comes to mind with this book. It starts out gradually and builds momentum to a gush of revelations in the final chapter or two - the deus ex machina of the author's excellent [b:Spin|910863|Spin|Robert Charles Wilson|http://d.gr-assets.com/books/1316636370s/910863.jpg|47562] finally resolved.
[a:Robert Charles Wilson|27276|Robert Charles Wilson|http://d.gr-assets.com/authors/1224814586p2/27276.jpg] rewards his readers with a picture story painted through small brush strokes that all contribute to the whole. The gestalt, to use a 60s term, of this book is built chapter by chapter in a manner that is patient and continuously-revealing. Plus, the romance(s) in the story-line are sweet like teenage summer crushes.
Basing mainly on the reviews here on Goodreads, I skipped the 2nd book in this series. [b:Vortex|9359796|Vortex|Robert Charles Wilson|http://d.gr-assets.com/books/1312034516s/9359796.jpg|13438392] is another slow-burning book that draws you in through the associated observations of its characters, an effective mechanism to build interest in the next big reveal. In the audiobook, there was some disorientation as to which of the two character pairs was on scene as both the past and the future characters were voiced so similarly. But overall, this is fine work that contrasts with flashier storm und drang fan favorites. I can't give it 5 stars as it doesn't quite reach the crest that [b:Spin|910863|Spin|Robert Charles Wilson|http://d.gr-assets.com/books/1316636370s/910863.jpg|47562] had prepared for it, but it gets close, or is asymptotic.