While HBO is keeping plot and character details for the sixth season of "Game of Thrones" are under especially tight wraps, one thing is certain: this is uncharted territory.

For the first time, the show will be able to tell parts of the story George R.R. Martin has not published in his A Song of Ice and Fire novel series, on which Thrones is based. Even though Martin may wind up publishing his sixth novel, Winds of Winter, just before the sixth season airs, the show and the books will be running parallel.

But Gemma Whalen, the actress who portrays Yara Greyjoy on Thrones, told British Comedy Guide the show will continue to deviate from the books' plotlines. So how might that be possible if they are at the same point?

[Potential spoilers to follow, but mostly recapping and speculation]

"Yeah, they've sort of... not run out of books really, but they've liaised with George RR Martin who writes the books, and gone off on their tangent, with his approval," Whelan told BCG. "So that's why people are even more interested in spoilers. It's funny isn't it, there's no other show like it."

Thrones viewers did not see Yara (Theon's sister whose names is actually Asha in Martin's books) in season five, but she is definitely going to be back for season six. When we did see her last, she was hightailing back to the Iron Islands after a failed mission to rescue Theon... err... Reek.

What Whelan may have been referring to is how Thrones completely skipped the Iron Islands story in the latest season. So while Thrones and the books are in the same place, there is a good chunk of story the former has not told.

[Continue reading here for the really spoiler-y stuff]