"A Dance with Dragons" is the fifth book in Martin's Song of Ice and Fire series. I believe it was published last year. There should be two more books to close this series, but even the author isn't sure about that. If you want to see what an immense industry this series has spawned, click here.
I've said it before and I'll say it again: if you haven't read these books already, you should. Yes, they can be a bit intimidating ("Dance" alone is 1,051 pages long), but they are a rewarding read. They feature a cast of hundreds, and the plot embraces many peoples, nations, and cultures.
The first half of "Dance" covers familiar territory. The previous book in the series, "A Feast for Crows" also dealt with a time period followed in the first half of "Dance." In "Dance" we get this same time period from several different perspectives, and we also learn what happened to Tyrion and Danerys after "A Storm of Swords." Many people have complained about this approach, but I think it works well, and morever adds another dimension to the previous book.
After the first half, many characters from "Feast" reappear. As the title promises, Danaerys's dragons also become more prominent, and Jon Snow assumes a role more central to the overall story. I'm thinking that in the next two books he's going to emerge as the hero of this thing, though I am always rooting for Tyrion. How could you not like Tyrion?
In my humble opinion, the only weakness in this book is the constant reappearance of characters seemingly "killed" in previous books. After a while this motif becomes repetitive, and I think it might have helped my suspension of disbelief if certain characters had stayed dead. Without death as a very real threat, it is difficult to feel as much for characters in mortal peril.
Just the same, this is a great book, and I am more than ready for a sequel!