Actor Richard E. Grant has been tapped to play a yet-to-be-disclosed role in "Game of Thrones" season 6. The 58-year-old Hollywood legend, who played the role of Simon Bicker in the BBC epic "Downton Abbey," is the latest British actor to be added to the HBO series' growing ensemble. 

HBO star Ian McShane will join the series in a mystery role while Max von Sydow is set to play the role of the Three-Eyed Raven. "UnREAL" Freddie Stroma was recruited to portray Samwell's brother Dickon Tarly while "Borgen" actor Pilou Asbaek will morph into Theon's uncle Euron Greyjoy. 

Just like McShane's role, the character the Grant will play is tightly under wraps. As per fan site Watchers on the Wall, there are a lot of roles he can play in "Game of Thrones" season 6. The "Withnail and I" star could become the Lord of the Horn Hill Randyll Tarly or Aeron Greyjoy, another one of Theon's uncle. He can fill in Lord Karstark, Smalljon Umber and many others. 

It's too tough to call which characters Grant will end up playing. The aforementioned publication says it could basically be any of the unfilled roles. According to Zap2it, the actor's talent agency removed "GoT" from his online acting resume, where it was suggested that his appearance in the series is more than just a one-shot deal.

In other related news, a drone by Eye in the Sky flying over the "GoT" set in Ballintoy, Northern Ireland has captured some behind-the-scenes footage of the filming of season 6. It captured the cast and crew and some breathtaking locations. Business Insider says that they might be shooting the Kingsmoot, the election of a new king by the Iron Islands captains, based on author George R.R. Martin's books.

"Game of Thrones" season 6 premieres next spring.