This is book four of the amazing Song of Ice and Fire series. Though, Martin mentioned at the back of the book how this is actually just one part of book four and the next is the second part of book four. This one tells the story of Cersei, Jamie, Arya, Sansa, Sam, Asha, some folks from Dorne, and Brienne. I missed some of the other characters but can understand why Martin decided to split this up. That said, I felt like there were entire chapters where nothing really happened.
I still enjoyed it and got sucked in, but would have liked there to be less filler.