First of all I very much liked the change from the book, and the introduction of something quite new, that hasn't been written yet. It must be very important for later storyline and story outcome (finale) otherwise they wouldn't mention it; I surely like the idea of white walkers and their possible role in story outcome. Also I can't understand all the bad comments that I read in IMDb. If book fans (and therefore show fans!!!) expect to see strictly the same story they already read, why they after all watch show, they already know everything? All in this episode is perfectly well executed and written. Some of the alterations that are even possible in the book are very well written and presented. There is nothing bad in this episode it is even one of the best of whole series; Game of Thrones episodes become better and better as the story progress! 11/10