According to Variety, Watts will be playing "a charismatic socialite hiding a dark secret," but Deadline had no real details about the role played by Whitehouse, only that this prequel will likely tell the origins of Game Of Thrones mysteries like the white walkers, and the extended family history of our favourite characters. Could Watts or Whitehouse be playing characters related to the ones we'll be seeing on screen when the show returns next year? HBO literally won't tell us.