"It involves a couple of characters, one of whom is dead on the show but not dead in the books," Martin teases about an upcoming plot development.

The Winds of Winter remain an unknown distance away, but whenever the book drops, it'll come equipped with a twist exclusively viewed on the printed page.

In an interview with IGN, author George R.R. Martin revealed that the next book in his A Song of Ice and Fire saga — the series on which HBO's Game of Thrones is based — will contain a pivotal plot development the show can't replicate. The reason is simple: The character at the heart of the twist is dead on Game of Thrones but very much alive in the books.

"It involves a couple of characters, one of whom is dead on the show but not dead in the books," said Martin. "The show can't do this stuff, because they killed a character that I have not killed."

It's a tantalizing clue, if not one that narrows down the playing field. As Martin admitted, his tease "doesn't narrow it down much because at this point, there are like 15 characters who are dead on the show but not in the books."

"I get all this stuff about being bloody-minded, but [showrunners David Benioff and D.B. Weiss] are bloodier than I am," he added with a laugh.

To Martin's point, there's a great divide between characters alive in the books but dead on the show, ranging from massive players, such as Barristan the Bold and Jojen Reed, to smaller players, such as Pyp and Grenn on the Night's Watch. Given the discrepancies between mediums, it's impossible to know exactly which characters and stories Martin's twist will impact and how.

Martin's latest update about his books comes almost two months after he revealed he would not be able to publish The Winds of Winter before the release of Game of Thrones' sixth season. In the interview, Martin said he's no longer thinking about his ability to finish the story ahead of the books.

"If I did have that thought, then I've already lost," he said. "The show has caught up and is in the process of passing me. Ideally I would have liked to have finished the books and have the story complete, but the show moves at a faster pace than I do. That's partly because I'm a slow writer and I've always been a slow writer, and also I've had a lot of distractions in the last few years."

Martin includes Thrones itself as one of his distractions: "I wrote several episodes in the early seasons. I'm a co-executive producer. That took up a considerable amount of time. But it is what it is. Ideally, I wish I could hold up The Winds of Winter right now and tell everybody to go out and buy it on Amazon or Barnes & Noble or their favorite local book seller, but it's still not done."

Fans will have to wait to see how Martin's story ends, whether on the show or in the books — but for what it's worth, not even Martin himself knows exactly how his song will conclude. "I know the broad strokes," he said, "but the devil is in the details."

Game of Thrones returns April 24 on HBO. Watch the full interview, below.