For the first three seasons, HBO's "Game of Thrones" stayed mostly faithful to the books...but that's going to change a little this season.

Maisie Williams, who plays Arya Stark, says,  "There's a few key plot twists and the way [the show's] writers go about it is different than the books.

"I think fans of the books will be a little confused, which I think is fantastic because it keeps it interesting for everyone."

(Spoiler Alert!)  One of those changes happened in the season premiere on Sunday...when Arya killed Polliver, the man who stole Needle from her in Season Two. In the books, it was The Hound who killed Polliver.

By the way, "Game of Thrones" isn't coming to an end anytime soon. HBO just ordered two more seasons, the show's fifth and sixth. No timetable was announced, but the fifth season will likely premiere next spring.

Last month, the show's creators said they'd like to see it run for seven or eight seasons...assuming HBO keeps ordering more.