** Possible Spoilers **
According to Game of Thrones fansite Watchers on the Wall, sources have confirmed that Mace Tyrell will head back to Westeros. Of course, this doesn’t mean a warm welcome from Olenna Tyrell, his mother, as she will be furious over Margaery and Loras’ imprisonment. She will confront Mace for doing nothing about it.
A complete stark family flashback is also confirmed by a reliable WOTW source, along with Hodor’s origin. A young Ned Stark has already been cast and will be played by 13 year old Sebastian Croft.
Ian McShane will neither play Aeron Greyjoy nor Randyll Tarly. He is rumored to play a small yet important role and will be seen with a group of outlaws in Season 6.