George R.R. Martin's "A Song of Ice and Fire" is one of fantasy's most involved and encompassing fictional narratives, with histories that span millennia, and despite the breakout success of HBO's "Game of Thrones" TV series adapting the novels, the show's creators now say they have no plans to produce a prequel series set in Westeros once they have wrapped their eight-season run.

In what has to be a tough break for all those "Tales of Dunk and Egg"-heads,  "Game of Thrones" executive producer/showrunner Dan Weiss pushed back against statements made by HBO Programming President Michael Lombardo during January's Television Critics Association press tour that a prequel series would offer an "enormous possibility to be mined."

After making news this week by announcing that Seasons 7 & 8 would feature less episodes than the show's traditional slate of ten (possibly as few as seven for Season 7 and six for Season 8), Weiss, who runs "Game of Thrones" with co-producer and fellow showrunner David Benioff, indicated that by going beyond the 73 hours of intended programming the two envisioned for the series, the show could see diminishing returns.

"At a certain point -- especially if it’s a serialized story -- it falls apart and loses its heat and its momentum because there’s a carrying capacity even a world the size of ours has," Weiss told Variety, adding, "When you reach that carrying capacity and you try to push it further, people start to wonder when this is going to be over and hope that it will be over soon so they can move onto the next thing. That’s not what we ever wanted."

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Season 6 of "Game of Thrones," which begins on April 24, will see the show explore new ground, as it will progress the narrative beyond Martin's novels while the writer continues to work on The Winds of Winter, the sixth installment of his planned seven-part series. Given Martin's deliberate pace in penning and releasing the books, there had been some speculation that HBO might look to previous works by the author set in the same "Game of Thrones" world, which would include stories such as "The Hedge Night," a novella set 90 years before the events of A Game of Thrones that was previously adapted by Marvel Comics. Now, though, HBO's Lombardo (who has disputed claims that the number of episodes in future seasons has been specifically decided upon) says that without the show's creators, the network will not produce more "Game of Thrones" television. "If it were not driven by [Benioff and Weiss], that [another show] would happen," he told Variety.

HBO's priority is maintaining quality, Weiss promises, saying, "They were concerned with making the best show they can because they know that’s the show that’s going to stick around for the longest."

But even for a show as beloved as "Game of Thrones," winter, as ever, is coming. Season 6 begins April 24, at 9 PM on HBO.