A Storm of Swords

Third in the Song of Ice and Fire series. And the second time I read it (first time was in 2006). Some big deaths in this one and some serious changes of fortune for Jon Snow, Sansa Stark, Tyrion Lannister, and Jaime Lannister. Why did Tyrion say what he did to his brother at the end of this one? And that final surprise... whoa.