Fans of the George R .R. Martin might have noticed a huge change in the Sansa Stark's storyline in episode 3 of "Game of Thrones" season 5, but showrunner David Benioff insisted that it's absolutely necessary to move the series along.

Spoilers for "Game of Thrones" season 5 ahead.

David Benioff, in an interview with Entertainment Weekly, said that as far back as season 2, they already decided to put Sansa Stark in direct path with Ramsay Bolton, the psychopath who tortured Theon Greyjoy and whose family was partly responsible for the death of her mother and brother.

He explained, "We really wanted Sansa to play a major part this season. If we were going to stay absolutely faithful to the book, it was going to be very hard to do that. There was as subplot we loved from the books, but it used a character that's not in the show."

But he said the change in storyline wouldn't have been possible if not for Sophie Turner's strength as an actress, and he attributed her casting to pure luck.

"We got very lucky in casting because it's so hard to cast good kids," the showrunner added. "Even if they come in and do a great audition, it's so hard to know if they're going to quite literally grow into the parts."

Bryan Cogman, who writes and produces for show, also teased some "Game of Thrones" season 5 spoilers as he said that in the George R.R. Martin novels, Sansa Stark wasn't maximized once she was already in Vale.

"That was not going to be an option for one of our lead characters," he said. "While this is a very bold departure, [we liked] the power of bringing a Stark back to Winterfell and having her reunite with Theon under these circumstances."

But marrying Ramsay Bolton may not bode well for Sansa Stark, at least based on what Jeyne Poole, he friend who was forced to marry Ramsay Bolton in the books, experienced with the psychopath, said MovieFone.

"Bad things happen to Jeyne as Mrs. Bolton, and fans are concerned that Sansa may face the same treatment," the article said. "In the book, a rescue attempt is launched to save 'Arya,' even though it's really Jeyne."

Watch out for more "Game of Thrones" season 5 spoilers which will be published here as they come along.