Since "Game of Thrones" has been on air, Bran Stark's prophetic dreams with a three-eyed raven had us guessing what the puzzle piece could mean. The boy still hasn't discovered its significance but it looks like Season 4 will reveal it soon. If you don't want full "Game of Thrones" spoilers, click away now.

Bran Stark’s Prophetic Dreams from A Song of Ice and Fire Series. IMAGE: Wiki Commons/Xeworlebi

"Game of Thrones" is based on a book series called "A Song of Ice and Fire" by George R.R. Martin and the three-eyed raven is also the Last Greenseer's name. The raven (crow in the books) is capable of seeing the past, present and future and lives beyond the Wall. He's very old that a Weirwood tree is literally growing through him and his purpose is to be of human service. He appears in Bran's dreams as a three-eyed raven to hone Bran's unique greenseeing abilities and to guide the boy to him. Sooner in "A Dance of Dragons," with Hodor and the Reeds, Bran makes it to the Last Greenseer who introduced himself as Brynden and revealed Bran's ultimate destiny, which is to become the Last Greenseer's replacement.

Theory has it that Brynden is Lord Brynden Rivers, also known as Bloodraven, believed to be the illegitimate son of Aegon IV Targaryen. He was legitimized later on and served as the Hand of the King and Lord Commander of the Night's Watch. The three-eyed raven's hardcore fantasy storyline also involves the Children of the Forest, which essentially are fairies. "Game of Thrones" focuses on human stories and keeps magic mostly in the background so it is unclear how much the Last Greenseer will be unchanged from the books. Odds are that he may appear in Bran's dreams as a human to explain to Bran the value of his mission in a less cryptic way. But would the enigmatic raven still play an integral role in the coming storylines and seasons even after his revelation?

In the GoT season 3, Bran parted ways with his brother, Rickon and Osha and went beyond the Wall to meet the raven and the reeds, afterwhich he meets Samwell Tarley who gave him info about the Wall and what to expect from the North. British actor Struan Rodger (Law and Order UK, Doctor Who) stars as the three-eyed raven in Game of Thrones Season 4 and will be important for Bran and events beyond the Wall later on.