The Twelve by Justin Cronin

I found this book a little hard to pick up--but I suspect it would be much easier had I read the previous book, The Passage, more recently. There's a lot of shifting in time in this book: one set of stories shows the actions of a devastated few immediately after the virals escaped--a pregnant doctor so traumatized by the attack she sees that she loses her mind, a lone wolf's escape from the penthouse apartment he'd holed up in, a group's response to the camps the US government set up to control the flood of refugees from infected areas--and the other set of stories is set about one hundred years later, as Amy and a variety of characters from the first book, attempt to destroy the 11 remaining, original virals. Once I figured out what was going on, I enjoyed this book, which was well plotted and well written.