The Long Mars by Terry Pratchett and Stephen Baxter (HarperCollins, 2014)
I just realized that I did it again – I read a book that is not the first in the series. This appears to actually be the third book, after The Long Earth and The Long War. This one stands alone a lot more easily than many science fiction books do, though. I am familiar with Terry Pratchett’s books about the Disc World but haven’t encountered Stephen Baxter yet. He does have quite a few books to his credit, so I don’t know if this is a typical “hooking up with an established author to sell books” scheme or not. Not that there’s anything wrong with that; it’s a great way to introduce new authors. Anyway, this is a sci-fi book with a fascinating premise. In about 2015, someone invented a way to instantly transport to the other versions of our world that are created at each decision point in time. This came in handy when Yellowstone exploded in 2045 and most of the United States needed a place to evacuate to. The Long Earth presumably tells the story of the original Step Day which preceded the explosion that led to the discovery of the Long Mars (in which some of the versions of Mars are more habitable than ours). There are some additional fascinating concepts which I will leave you to discover when you read this book. In any case, it’s well done and hard to put down, but not as nonsensical and hilarious as you might expect from Terry Pratchett – the influence of Stephen Baxter makes it slightly more serious.