This is a neat little set of apocalypse stories. While I haven’t read the two subsequent books, my understanding is that most of these stories are continued in the later books, but they are also stand-alone stories, about the time and moments right before the end (or effective end) of the world. Some are clever, some are a bit obvious, but most are worth reading.
My only caveat is that several of the stories suffer from the usual major plot defect of modern science fiction, since 1990 or so—monolithic, un-ironic conformity on social issues, always beating the reader over the head with whatever today’s liberal cause is. Here, naturally, it being 2014, gay characters (all of whom are wonderful heroes) abound. It being 2014, though, trans characters are lacking, and gender fluidity is not portrayed. So my conclusion is that the authors are evil bigots, and I hope they rush out stories focusing on the apocalyptic tribulations of the gender dysphoric, ASAP. And, of course, Christians are never portrayed positively; all conservative types are bad; etc. On the other hand, no story has global warming as the cause of the end of the world, so that’s something.
But if you simply ignore this, which you have to do anyway every day just watching the news, you can enjoy the stories.