Best-selling author George R. R. Martin has implied in the past the possibility that "The Winds of Winter" being the last book in his mega hit series "A Song of Ice and Fire."

Although originally planned as a trilogy, "A Song of Ice and Fire" is now five books in, with "Winds of Winter" set up as the sixth book.

As per Bustle, Martin referred to the original trilogy's final book as "The Winds of Winter." While it has become the sixth volume in the series, the fact that it was the name of the final installment hints that it has everything Martin needs to wrap up the whole series.

While the 68-year-old author has announced "A Dream of Spring" as the final book, he said that there's a possibility of the novel not being released at all.

"I'm as firm as I am... until I decide not to be firm," the author told Entertainment Weekly back in 2011. Around that time, the publication reported that Martin "already made some headway" on "The Winds of Winter."

As fans already know, the HBO fantasy series "Game of Thrones" inspired by Martin's masterpiece, has now overtaken Martin.

The latest season of the mega blockbuster series revealed some of Martin's biggest twists and plot points in "A Song of Ice and Fire," leading to the belief that "The Winds of Winter" has been spoiled by the show.

Martin has emphasized that the show won't spoil the novel and that he has some tricks up his sleeves and big twists for "The Winds of Winter."

"Game of Thrones" has killed off characters that are very much alive in the books. One of which is Stannis Baratheon, who alone can change the outcome of the North arc.

Martin has already said that "The Winds of Winter" will feature a twist involving a character that is dead on the show. This, alone, shows that there's a lot more to look forward to in "The Winds of Winter."