As we count the days leading up to Game of Thrones' seventh season, we find ourselves craving more and more information — blame this year's delayed premiere. There are a handful of cliffhangers that need resolution, but right now we're more concerned with the new storylines. There are a couple of new faces coming to the show, but only one of them will play a new character. (Tom Hopper is just taking over the role of Dickon Tarly, since Freddie Stroma left the show to star on Time After Time.) Of course, Ed Sheeran is making an appearance, but it will more than likely be a short cameo.
This leaves one new actor with potential for a meaty new part: Jim Broadbent. HBO is generally very tight-lipped about Game of Thrones spoilers, but Broadbent himself spilled a bit about the role in March. "I'm a maester, an archmaester," he told ScreenCrush. "I'm an old professor character." He also divulged that he shot five episodes (there are seven in the season), he appears in "one major scene each episode," and the majority of his scenes are with Samwell Tarly.
All of these hints point to a character in the books who is known as Marwyn the Mage. The archmaester lives at the Citadel (where Samwell has just arrived on the show), and upon hearing Samwell's story, Marwyn leaves to seek out Daenerys. Before departing, he orders Sam to finish his studies then immediately return to the Wall.
Of course, it's entirely possible that we could be meeting other new characters, as well. HBO is good at keeping secrets!