The release date for "Winds of Winter" remains a mystery and that means producers of the HBO hit series, "Game of Thrones" might have to invent a different ending.

George R. R. Martin acknowledged this possibility during the Q&A at the Sasquan science fiction convention in Spokane, said Geekwire.

"Anything is possible," he said.

The author has told Entertainment Weekly that he's trying to set for himself a target for the "Winds of Winter" release date and hopefully, it should be prior to the airing of the "Game of Thrones" season 6 in April next year.

He admitted that the pace is moving quickly for the show ("like a jet locomotive"), as well it should. But comparing his writing pace to the pool of writers for "Game of Thrones" is unfair.

"They're writing 60-page scripts, I'm writing 1,500-page novels. So who the hell knows?" he said. "I'm just going to tell my story, and they're telling their story and adapting my books, and we shall see."

George R. R. Martin said there was a point in time when he was worried about the pace of the show and it's impact on the release date of "Winds of Winter."

"Then I said, to hell with that," he said. "Worrying about it isn't going to change it one way or another. I still sit down at the typewriter, and I have to write the next scene and the next sentence ..."

"I'm just going to tell my story, and they're telling their story and adapting my books, and we shall see."

With that said, the author conceded that the producers might go to an alternate ending with "Game of Thrones" with what he has envisioned for the books. It was reported earlier that George R. R. Martin already revealed to producers Dan Weiss and David Benioff how the novels are going to end.