Game of Thrones” has cast Oscar winner Jim Broadbent for a mystery Season 7 role, Variety has confirmed.

HBO declined to reveal any character details for Broadbent’s role, except to tell Entertainment Weekly, who first reported the casting, that it will be “significant.” The network was equally cagey about Ian McShane’s brief but pivotal part in Season 6, which turned out to be vital in reintroducing the fan-favorite character of The Hound, previously thought dead.

Now that the hit series has outpaced George R. R. Martin’s novels, fans are in uncharted territory when it comes to new character additions, and it’s likely that the producers will be even more spoiler-averse than usual to protect the show’s secrets as “Game of Thrones” embarks on its penultimate season. Season 7 has already been confirmed to be shorter than previous years, totaling seven episodes instead of 10, with HBO confirming that Season 8 will be the fantasy hit’s last. Season 7 will also have a later premiere date than its usual April bow, since the show is starting production later in the year to take advantage of the chillier weather needed to portray winter’s long-awaited arrival in Westeros.

The HBO hit is nominated for 23 Emmy awards, including first-time nods for Kit Harington and Maisie Williams, who shared her thoughts on the show’s impending ending and her hopes for Season 7 in a recent interview with Variety.