If you're an engaged fan of one of HBO's big-ticket shows, chances are you've participated in the wild world of fan theories, which dominate internet real estate in the time between episodes. Game of Thrones is perhaps the most prominent example of this phenomenon, and it's hard to call yourself a true Thrones head these days if you're not trading secrets among your fellow fans in the hours following a new episode.

"Eastwatch" may not have been the action-packed, dragon-fueled extravaganza "The Spoils of War" was, but the follow-up to one of the series' best episodes teased several massive reveals as we approach the show's conclusion. With so little time between now and the finale, it didn't appear we had a lot more time to add any more power struggles or points of contention. In true Game of Thrones fashion, however, "Eastwatch" just changed the stakes of the end game with the end game actually in sight.

If you paid close attention on Sunday night, you may have picked up on these important developments in "Eastwatch." If not, you know we have you covered.

WARNING: The following writing will contain massive Game of Thrones spoilers.

Jon Snow has a stronger claim to the Iron Throne than Khaleesi

Reluctant as he has been to actively engage in the Westeros power struggle, Jon Snow has proven himself a respected leader and a willing diplomat when called upon to reach across the aisle. Those might be skills he'll need in surplus in the near future, because a small aside about his heritage in "Eastwatch" revealed he has the strongest claim to the throne in all of the seven kingdoms.

Jon's lineage has been one of the threads at the core of the show, and in the Season 6 finale, "The Winds of Winter," we learned the identity of his father was none other than Prince Rhaegar Targaryen, the heir to the Iron Throne prior to being killed by future king Robert Baratheon. This was a big development in and of itself, but within the Game of Thrones canon, it was believed Jon was an illegitimate child conceived by Lyanna Stark against her will. In fact, her alleged kidnapping by Targaryen was a major spark in the conflict that put Robert Baratheon on the Iron Throne in the first place.

This all changed last night. While her lover Samwell Tarly was busy preserving documents for Archmaester Ebrose, Gilly stumbled upon a massive development among the texts—Targaryen had at one point had his marriage annulled, and was later remarried during a secret ceremony in Dorne.

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Why does this matter? The vision in which we saw Lyanna Stark give birth to Jon took place at the Tower of Joy, located in Dorne. In effect, Gilly's reading revealed that Targaryen and Stark had a legitimate relationship and marriage after all, which would make Jon Snow not a bastard at all, but the rightful heir to the Iron Throne. It was always interesting that Rhaegar left members of his Kingsguard behind to protect a pregnant woman in Dorne, but now it makes sense, because he was protecting his legitimate son and possible heir to the kingdom.

With this information on the table, Jon now has a stronger claim to the Iron Throne than Daenerys Targaryen herself, who has repeatedly asked Jon to bend the knee and accept her as the true ruler. Though Jon has been hesitant to take any power he is not awarded by the people, this sets him up for conflict with the woman—and his relative—who he has finally come to an understanding with.

Forgetting that power struggle for a second, Jon also just set off on a borderline suicide mission to end the episode, putting a legitimate claim to the throne at risk for the sake of all humanity. That bravery and his lineage could be the force that unites the people of Westeros, or it could be a bout of stupidity that leaves him dead, and humanity in peril. Now that we know this, only one thing is clear: the people need Jon Snow.

The Stark sisters might be driven apart by Littlefinger

With Jon traveling all across Westeros in an attempt to save humanity from the White Walkers, Winterfell has been left in the hands of Sansa Stark, and she has since been reunited with several of her younger siblings. And while it was heartwarming for them to reunite, it's easy to forget they haven't always seen eye-to-eye throughout Game of Thrones.

Knowing of their sibling history, the always-scheming Littlefinger is working to plant more seeds of doubt in the relationship between Sansa and Arya Stark. Through espionage, the latter discovered Littlefinger had obtained a letter written by the former as a younger woman, and on first glance, it shows Sansa as a traitor to her family name. The letter reads as follows:

Robb, I write to you with a heavy heart. Our good king Robert is dead, killed from wounds he took in a boar hunt. Father has been charged with treason. He conspired with Robert’s brothers against my beloved Joffrey and tried to steal his throne. The Lannisters are treating me very well and provide me with every comfort. I beg you: come to King’s Landing, swear fealty to King Joffrey and prevent any strife between the great houses of Lannister and Stark.

This appears to reflect poorly on Sansa's loyalty to her family, but consider the context at the time of writing. With her father staring down treason charges and eventual death, Sansa was told her father's fate rested on her shoulders. Fearing he would die if she didn't cooperate, Sansa wrote the letter in the manner Cersei Lannister demanded of her. Ned Stark ended up dying anyway—the Lannisters do not fuck around—but the letter was a daughter's last-gasp attempt to save a family member, not the undying pledge of loyalty to the Lannister family it looks like. 

Littlefinger knows this since he was in the damn room when it happened, but he also knows Arya is unaware of this, and that the two sisters have not exactly been in lockstep throughout their lives. While Sansa remained in the comfort of King's Landing, writing letters that appear sympathetic to the family that killed her father, Arya was living on the streets, fighting for her family name and training herself to dismantle the Lannisters at all costs.

Feeling himself being pushed out of the picture by the arrival of family in Winterfell, Littlefinger is injecting more chaos into a tense situation, hoping it will give him the opening he needs. A healthy conversation between Arya and Sansa could clear all this up and see them both turn on Littlefinger, but given Arya's penchant for murder and mayhem, betting on the Stark women to sit down for a peaceful cup of tea seems unlikely. Littlefinger might come out of this with more power, against all odds.

A big death has already been hinted at for next episode

By recent Thrones standards, "Eastwatch" was relatively tame on the death front. A couple important members of House Tarly and a pair of guards aside, most movers and shakers in the seven kingdoms held onto their lives in preparation for big battles to come.

One of those battles will be north of The Wall, involving a group that is the rough equivalent of a mash-up between Suicide Squad and Game of Thrones. A group of the show's greatest warriors—Jon Snow, the Hound, Jorah Mormount to name a few—are seen banding together in the show's final moments, dropping any differences between them in a mission to save humanity as they know it. But after the episode's conclusion, we see a tease that may spell doom for one member of the party, who we only just reunited with in "Eastwatch."

In the trailer for the sixth episode of Season 7, this rag-tag group of heroes is seen battling against the White Walkers. There's just one small detail that stands out: the weapon being used by the Hound. 

In the clip of him absolutely crushing this White Walker, the Hound is spotted using a warhammer, which is not the usual choice of weaponry for the acclaimed swordsman. This is even more notable, of course, after Gendry Baratheon jumped back into the fold in "Eastwatch," wielding a warhammer himself. Could Baratheon be a goner in this Avengers-style mission north of The Wall?

The evidence is pointing that way. It would be cruel for Robert Baratheon's bastard son to die two episodes into a return—remember, we haven't seen him since the show's third season—but there haven't been many surprising deaths of late. Bringing Gendry back and having him bond with Jon Snow would only serve to make it more painful if he meets a swift end at the hands of humanity's greatest threat.

Of course, this is a lot more speculative than the other major developments in the episode, but if he were to die, this would spell the end for House Baratheon, even if Gendry is a bastard son. Gendry admitted in "Eastwatch" he's more of a fighter than a warrior when he asked to come north with Jon, and we just might find that out the hard way next episode.