And, of course, I was going to finish the trilogy. This is the best mystery series I've read in a long while. Even if the second book didn't fulfill my expectations, I had every reason to believe the third would. (See every diatribe written about second book problems.)
And he pulls out all the stops. Each and every situation in this volume made sense. The people you meet and the events that occur are complete tragedies in and of themselves. In one sense, it's like reading a series of short stories created into a novel - and only the best can do this well (see Olive Kitteredge). He extends the mysteries from the previous two novels into this one, and he makes sure you are allowed to feel for each character in the mysteries, even as you retain the sense of the doomed world and the oddity of caring about doomed people.
I did see the solution to the ultimate mystery coming (and by ultimate, I don't mean that asteroid), and I feel that he didn't obscure it as well as he needed to. It's obvious from the moment you meet the first character in that scenario, if you wonder about the potential for the scenario as much as I did.
Enough obfuscation, since writing anything revealing defeats the purpose of the review! Enjoy this trilogy and hope that he writes more like them.