Theory: Bran’s new ability to witness — and affect — events throughout time via greenseeing might mean that he is/was/will be responsible for building The Wall, aka the device keeping the White Walkers away from everyone else for all these years. After all, the structure’s architect/founder of House Stark (and the mythical figure for whom young Stark is named), is… Bran the Builder.
Evidence: Young Ned could hear his future son during the Tower of Joy flashback, so what’s to say others won’t be able to, as well?
Likelihood we’ll get an answer in the season finale: Almost zero. It would make sense that “Hold the Door!” will be Bran’s big greenseeing moment of Season 6. Maybe next season?
LADY STONEHEART IN THE HOUSE?
Theory: Catelyn Stark, who met her end at Season 3’s Red Wedding and who in the books is resurrected as the vengeance-seeking Lady Stoneheart, will appear in all her undead glory.
Evidence: The Brotherhood Without Banners’ Beric Dondarrion is the man who revives Cat in the books, by trading his life for hers. And guess who showed up in “The Broken Man”? (Yes, we know that the timing is all kerfluey. WE JUST WANT HER BACK SO BADLY.)
Likelihood we’ll get an answer in the season finale: Slim. Though wouldn’t a Stoneheart sighting be the perfect cliffhanger for the season?
SANSA’S BABY BOLTON?
Theory: Sansa is pregnant by her abusive late husband, Ramsay Bolton.
Evidence: Sansa’s recent conversations with Littlefinger and Ramsay, both of which implied that she was fundamentally different in the wake of sharing the rapist’s bed.
Likelihood we’ll get an answer in the season finale: Zero — because we alreadyhave an answer: Sansa was very certain in “Battle of the Bastards” when she told Ramsay that the Bolton family line would die with him.
Theory: Jon Snow is really the son of Rhaegar Targaryen and Lyanna Stark. Before her death, Lyanna made brother Ned promise to raise the boy as his own in order to protect him from the wrath of Robert Baratheon, to whom she was promised in marriage and who wanted all Targaryens dead.
Evidence: The Tower of Joy scene from the “Oathbreaker” episode, in which Bran watched young Ned fight his way to the tower as Lyanna cried out; it’s commonly believed that she was in childbirth at the time.
Likelihood we’ll get an answer in the season finale: Unclear. Though if the series does check in with time-traipsing Bran once more this season, what a great way to do it, eh?
R+L=J AND M
Theory: Exactly like the previous theory, except that Lyanna had twins — a boy and a girl — and Meera Reed is really Jon’s sister.
Evidence: Howland Reed, the man who raised Meera, was the only other man to survive the fight at the base of the Tower of Joy. He could have taken the baby girl home, while Ned brought Jon back to Winterfell to raise.
Likelihood we’ll get an answer in the season finale: Almost zero. This theory is more tenuous than some of the others, and even if it is true, it would make sense to save the twin reveal for a later time.
JAIME IS VALONQAR
Theory: Remember in Season 5, when Cersei flashed back to visiting a fortuneteller when she was a little girl? The HBO series left out one part of the prophecy that readers of George R. R. Martin’s books have focused on for years: Cersei will be killed by the valonqar, or “little brother/sibling” in High Valyrian. Many take this to mean that Jaime, who was born a few moments after his twin sister/lover, ultimately will be the person responsible for her death.
Evidence: In the show? None, really. But it would be quite ironic/poetic.
Likelihood we’ll get an answer in the season finale: Not great. The last time we saw Jaime, he was nowhere near King’s Landing, and Cersei is stuck there.
TOMMEN IS VALONQAR
Theory: Same as Jaime, except the “little brother” isn’t Cersei‘s little brother… it’s her son, who’s the youngest of her children.
Evidence: Again, nothing concrete in the HBO series.
Likelihood we’ll get an answer in the season finale: You could make a case for Tommen, under the High Sparrow’s influence, having his mother executed. But the prophecy also mentions the valonqar “shall wrap his hands around your pale, white throat and choke the life from you,” and we just can’t imagine the boy king having the physical strength or mental conviction to do it.
JON SNOW IS AZOR AHAI
Theory: Jon is The Prince That Was Promised, the legendary warrior whose second coming is prophesized by Red Priests and Priestesses like Thoros of Myr and Melisandre.
Evidence: He seems pretty damn unkillable, doesn’t he? (See also: That crazy near-miss sequence from “The Battle of the Bastards.”)
Likelihood we’ll get an answer in the season finale: Nope. That kind of reveal is the stuff of series finales, right?
MAD QUEEN CERSEI
Theory: In an effort to thwart the High Sparrow’s grip on King’s Landing, Cersei will ignite the caches of wildfire hidden under the city, essentially destroying the place.
Evidence: As recently as “The Battle of the Bastards,” Tyrion mentioned the highly flammable, incredibly unstable liquid — which Mad King Aerys was planning to use on his kingdom, which is why Jaime killed him back in the day. Also, the rumor that Qyburn quietly confirmed for the queen regent may have something to do with the fact that Aerys’ stores of the chemical are still hidden beneath key locations in King’s Landing — including the Sept of Baelor, where Cersei’s trial is to take place.
Likelihood we’ll get an answer in the season finale: Pretty good. Bran’s visions included seeing wildfire ignited in the city, and we all know that Cersei is the “burn ’em all!” type when she feels like she’s backed into a corner.