George R.R. Martin has released a chapter from his upcoming book Winds of Winter on his official website. The book is to be the sixth installment in the Song of Ice and Fire series, which serves as the basis for the hit HBO fantasy series Game of Thrones. This would not be the first excerpt from Winds of Winter, as Martin has released a handful of other chapters and appears to replace them with new excerpts, so they’re never posted at the same time.
You can read the newest chapter, which is from the point of view of Sansa Stark (under an assumed name), here: http://www.georgerrmartin.com/excerpt-from-the-winds-of-winter/
No release date has been set for Winds of Winter though it has been estimated it will come out in early 2016. But, until then, fans can look forward to the fifth season of Game of Thrones premiering April 12 on HBO. If or how this excerpt might fit into the new season is unknown, so be warned of potential spoilers if you choose to read.