Fans have been waiting so long for the release of the sixth installment in George R.R. Martin's "A Song of Ice and Fire" book series. However, there has been no word yet as to when exactly "The Winds of Winter" will hit the shelves. What could be causing the delay?

A fan theory about the cause of delay in the book's much-awaited release has gone viral recently. The "A Song of Ice and Fire" thread on Reddit suggests that Martin may be adding some twists in the sixth book, which could greatly affect the storyline. This could be the reason why the writing has been taking longer than usual, given that "The Winds of Winter" was expected to be released about six years ago. If this theory turns out to be true, the events in the book could totally be different from the events in the "Game of Thrones" TV series.

Although it's unclear when the "The Winds of Winter" will finally be published, the author has been posting excerpts from the novel on his website since 2010.

However, there may also be another reason for the delay. It could be because Martin has been working on another material, "The Sons of the Dragon," a short story that serves as a prequel to "Game of Thrones," according to The National. It is a part of the anthology "The Book of Swords," which tackles "fantasy's golden age of sword and sorcery."

Even though Martin has stated that he believes "The Winds of Winter" will be coming out this year, fans must take this information with a grain of salt as he also said the same thing back in 2016, but later took it back as he had not finished writing yet.

Many fans believe that the book will be released in September as the author celebrates his 69th birthday. However, there is also speculation that it's going to be on his 70th instead.