In “Game of Thrones” Season 4, episode 4, “Oathkeeper,” the series featured two major departures from the “Song of Ice and Fire” novels that will drastically change how the show is viewed by fans who have read the books and those who have not. The ending scene in “Oathkeeper” revealed the most in-depth look at the White Walkers and could hint at the future of the series.

In interviews leading up to “Game of Thrones” season 4, the series creators, David Benioff and D.B. Weiss, discussed meetings with George R.R. Martin which covered the end of the “Song of Ice and Fire” series. While Benioff and Weiss may not know every detail about the fate of the characters and Westeros, they have enough knowledge that will shape the future of “Game of Thrones” and how the story plays out in the HBO series.

In “Oathkeeper,” viewers watch as a White Walker, riding a horse, takes the baby boy away from Craster’s Keep, crosses a frozen sea and places the sacrifice on an altar of ice. Another White Walker takes the baby and, with a touch of his finger, turns the young boy into a White Walker. The scene is entirely new and is the best look at the White Walkers in either the novels or the series.

Any knowledge of the White Walkers is usually revealed in stories or through tales passed down through generations and their history is unknown. The White Walkers are not undead but a human-like being, but they can turn the undead into wights that they can control, and their presence is usually accompanied by ice or snow. In the “Game of Thrones” series, the White Walkers were seen in Season 1 and Season 2 but the end of “Oathkeeper” reveals more of their origins, including their possible location and type of society.

Reddit users were quick to discover the identity of the White Walker in the final scene. Based on screenshots, the “Game of Thrones” viewer’s guide for “Oathkeeper,” the White Walker that touches the baby is revealed as the Night’s King, although that description was changed to a Walker. The Night’s King is a former Lord Commander of the Night’s Watch who fell in love with a White Walker and made her his queen. In “A Storm of Swords,” Bran shares the stories about the Night’s King and the terrible things he did during his reign, including sacrificing babies.

Whether or not there are more White Walkers in "Game of Thrones" season 4, Benioff and Weiss have proven they are not afraid to diverge from the "Song of Ice and Fire" series. In addition to the final moments of "Oathkeeper," the scene at Craster's Keep was not in Martin's novels.