Before new Game of Thrones episodes finally debuted last month, the off-season was easily the most secretive in the show's history. Since the fantasy drama has caught up with George R.R. Martin's novels, fans were left in the dark about what will happen in Westeros during Season 6. The show held its annual Comic Con panel last summer, but unlike previous years, the producers didn't unveil any new cast or characters. HBO even stopped sending out advanced screeners to press members, since the first four Season 5 episodes leaked early, just before the premiere last spring. As it turns out, some of the cast members weren't even in on the show's big secret yet. Be warned, there wil be SPOILERS if you didn't watch this past Sunday night's episode of Game of Thrones, so read on at your own risk.

At the end of Home, fans finally learned the truth about Jon Snow's death (Kit Harington), as he was resurrected by the red priestess Melisandre (Carice Van Houten). We aren't sure what will happen with Jon Snow throughout the rest of the season, but Kit Harington revealed yesterday that Season 6 will be the biggest yet forthe character, with many speculating we may finally learn who Jon's real mother is. As it turns out, Jon Snow's fate wasn't even shared with the rest of the cast for nearly a full year.

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After the Season 5 scripts were sent to the actors in the summer of 2014, the cast found out that Jon Snow was going to be killed. Two weeks later, showrunners David Benioff and D.B. Weiss told Kit Harington that he would be coming back to life, but they swore him to absolute secrecy. He was forced to tell his cast mates that he would be leaving the show, with one of his co-stars, Liam Cunningham, telling him to "f--k off right from the start." Here's what he had to say about keeping this secret for nearly a full year, until the Season 6 scripts were sent out last summer.

"At first I thought I would find it fun. This will be a fun game. But I had to lie to a lot of close friends and cast members and crew. The longer it went, the more I felt like I was betraying them. So I did end up letting people in, slowly. Sophie Turner, bless her, wrote me a really long letter about how much she loved working with me - and I still got it. That made me chuckle."

After Jon Snow's death in the Season 5 finale last June, many fans weren't convinced that he was actually dead, since he was too important to the show, and they still haven't solved the mystery of his mother's identity. While we don't know for sure, it seems possible that Jon Snow's lineage may be addressed throughout this new season, with hints surfacing that a fan theory dubbed "R+L=J" may be true. This theory claims that Jon Snow's parents are actually Rhaegar Targaryen and Lyanna Stark, Ned's sister, which would give Snow a very strong claim to the Iron Throne, since he would be part Stark and part Targaryen.

The theory claims that, before Lyanna died, she made Ned promise not to tell anyone about the true heritage of this child, with Ned returning from battle with this child he claimed was his bastard. Last week's Home gave us our first look at a young Lyanna, through one of Bran Stark's (Isaac Hempstead Wright) greensight visions, with next week's episode Oathbreaker delving into the battle of the Tower of Joy, which was sparked by Rhaegar Targaryen's abduction of Lyanna Stark, which this theory claims resulted in Lyanna giving birth to Jon, as she made Ned promise not to tell anyone about Jon Snow's true lineage. Stay tuned for more on Game of Thrones before "Oathbreaker" debuts on Sunday, May 8 at 9 PM ET on HBO.