How best to save humanity from the mess it's gotten itself into? And do the ends ever justify the means? Those are the basic question posed here, and the author thankfully avoids most of the cliches and tired old tropes of most of this kind of disaster fiction. It is very well written, with two protags who seem at first glance to be complete opposites in most ways except that they are geeks and misfits. Their relationship is well developed, and what little sex and romance is in the book seemed neither mushy nor squicky to me but instead more realistic than most fictive depictions of same. The ending was a bit abrupt, and there were a few loose ends left dangling. I don't see quite how the ending can be used to springboard the story to a second book but hope I'm wrong about that because (view spoiler)[Peregrine & The Tree (hide spoiler)]! The system of magic wasn't as well defined as I'd have liked; bullying played a big part, especially in the early chapters and was difficult for me; there was a lot of scientific and technical jargon tossed around which went right over my head. Happy to report that none of that took away my enjoyment of the story. I recommend this to scifi geeks and just about anyone who enjoys well-written scifi and/or fantasy.