If you ever want to know something, just go to Professor Slughorn.
Whitney asked Slughorn himself, actor Jim Broadbent, about his mysterious “Game of Thrones” Season 7 role, and the actor was as forthcoming as though Whitney had been in the Slug Club.
“I’m a maester, an archmaester. I’m an old professor character,” he said.
The actor also revealed he does scenes with Sam Tarly (John Bradley) and appears in five episodes, adding, “I did sort of one major scene in each episode.”
Thus far, it’s been theorized that Broadbent will play Marwyn, who’s an archmaester of the Citadel in George R.R. Martin’s books.
Broadbent’s answer basically confirms that. If he is indeed Marwyn, prepare for him to make a big impact.
In the books, Marwyn meets with Sam, hears about how Maester Aemon wanted to get support to Dany, and supposedly heads off to find and possibly counsel the Mother of Dragons. Marwyn’s methods are seen as somewhat unorthodox compared to other maesters, so who knows what he’s up to for sure? But the dude appears to be sympathetic to dragons.
There might be a problem, though.
In the books, the maegi Mirri Maz Duur supposedly studied under Marwyn. Fans will probably remember that Dany burned her in a fire in Season 1 to help bring her the dragons to life.
An awkward meeting could be coming ...