A 'Game of Thrones' actor has a theory on Sam Tarly and the Citadel's gyroscope

After a long journey, Samwell Tarly finally made it from Castle Black to Oldtown during the season six finale of "Game of Thrones."

And though his appearances were brief, only a few minutes in three different episodes, Sam's journey is one of the most exciting and fulfilling plotlines in HBO's hit show.

Sam left Castle Black at the end of season five to travel to the Citadel and train to become a maester so he could return and serve Lord Commander Jon Snow. Jon is no longer Lord Commander - having died, been resurrected, renouncing his place in the Night's Watch, and becoming King in the North - but Sam arrives and is immediately astounded at the immensity of the Citadel's library.

Upon entering, he sees a massive, elaborate gyroscope hanging from the ceiling, which some fans have pointed out is similar to the astrolabe featured in the show's title sequence.

John Bradley, who portrays Sam, didn't know the gyroscope was hanging in the Citadel until he watched the episode, but in an interview with the Hollywood Reporter, he explained a theory that viewers are experiencing the story of "Game of Thrones" through Sam.

"One theory is that what we're seeing now and how we're experiencing 'Game of Thrones' is Sam telling the story of 'Game of Thrones,'" he said. "If you take the logic of the story now, the story of Westeros and the story of the battle for the Iron Throne, it would be a book in that library. The visual motif of that is you're about to be told a story - the sense of an idea of being told a story, and people gaining that knowledge, the way Sam is absorbing knowledge in the library."

Bradley described the Citadel as the first place where Sam "feels at home with himself and doesn't have to pretend to be anything he's not" and as a culmination of Sam's success story, along with Gilly.

"When we first meet Sam, his ambitions for life are so modest ... All he wants in life is to be loved, be accepted and do the things he enjoys ... So the achievement of falling in love, keeping the person he loves close to him and going to a place where he's accepted - they're all ambitions he never thought he could achieve," he said. "It's a pipe dream. You find him at the end of season six having achieved all of that through one method or another. It's been a very slow and progressive success story for Sam."

You can read the full interview here.