Braavos: The explanation of the origins of the Faceless Men is loosely based on the Kindly Man’s account to Arya in A Feast for Crows, while the play rendering a dramatic (and not very accurate) version of the events in King’s Landing during the novels is inspired by a released chapter from The Winds of Winter (in particular, Lady Crane is named).
Iron Islands: The kingsmoot is loosely inspired by that of A Feast for Crows, although Theon was not present, there were other claimants, and Euron convinced the captains and lords to elect him based upon an apparently-magical dragon horn in his posession.
Possible Developments in Future Books
Beyond the Wall
: We have speculated in the past as to the origins of the Others, suggesting they are the creation of the children of the forest. While the show going this route is not proof of Martin’s intentions, it seems to us that it remains a very reasonable possibility. As to the events in the episode, including the death of the three-eyed raven, the flight from beneath the Weirwood, and the revelations concerning Hodor, we remain under the belief that Bran is unlikely to ever leave… but it seems confirmed by the producers that the novels will indeed reveal “Hold the door” is the origin of Hodor’s name, and that this will be a heartbreaking circumstance. One possibility in our minds is that this will be revealed with Hodor having been taken (by Bran, through skinchanging) to some other place while leaving Bran at the weirwood. Another may be that this is an event for the end of the series, when forces of the Others directly attack the weirwood to prevent Bran from doing something magical that could greatly affect the outcome of their war against men, and Hodor is conducting a last stand of some sort. Similarly with the fate of Summer—it feels like it may happen in the novels, but not quite in this way (which seems dictated by the publicized difficulties the production has with having them present on camera). Only time will tell the full truth of it.
The Wall: Given the substantial differences in Sansa’s position in the show and the novels, it’s indeed possible that the Sansa of the novels may have some uncertainty regarding Jon Snow and his role in events in the North with regard to Winterfell.
The Wall: Sansa is not likely to be on the outs with Littlefinger if she does ever make a claim to Winterfell from the Vale. Similarly, Riverrun and the Blackfish are not in a position, in the novels, to provide even notional assistance to the Starks at this point in the novels.
Iron Islands: The drowning ceremony involves a priest of the Drowned God resuscitating the faithful with a primitive kind of CPR, which the show omits for a more inexplicable return. The Iron Fleet already exists in the novels, and while Asha does escape the island with men loyal to her, it’s not even a substantial fraction of the total Iron Islands fleet. Euron’s casual way of speaking of murdering his nephew and niece—and the way this seems easily accepted by the Ironborn—is very exaggerated compared to the novels, where kinslaying is still seen is a major crime.
Braavos: Unlike on the show, in A Dance with Dragons we know that the Kindly Man will send Arya to Izembaro, the chief mummer, to train further in the guise of what will later
Vaes Dothrak: Jorah is not infected with grayscale in the novels.
Meereen: There is a High Priest of R’hllor in Volantis named Benerro, but he does not venture to Meereen in the novels. He does preach in favor of Daenerys, part of the reason the Old Blood who rule the city move against her to end her disruption of the slave trade before the many slaves of the Free City get notions of freedom, but it seems a show affectation that someone in Meereen will negotiate with a high priest to spread propaganda on their behalf.