Joining the Blackfish will be Edmure Tully, Catelyn Stark's sister. He will be involved at Riverrun in Season 6, though it's unclear as to whether the show will zip straight to the Tully men or follow the path of the army marching up to siege the city. Either way, it's exciting for book readers who will know what to expect but thought that the storyline would be omitted after it failed to appear in Season 5. If you're going into Season 6 blind, brace yourselves...