Fair warning: This post contains spoilers for how Game Of Thrones is probably going to end, but just know that even a regular Game Of Thrones fan might have trouble understanding it. Reddit user zyuko22 — who claims to have previously predicted the wall coming down at East-watch-by-the-Sea and the fire fight above the wall — has a new theory up their sleeves. It all hinges on one of the final moments in the season 8 premiere when Beric Dondarrion (Richard Dormer) killed the wight boy (seen earlier in the episode as the small Umber boy), setting that whole creepy pattern of arms ablaze. Turns out, this may not have just been for show, but actually the key to how the entire franchise ends.
Basically, according to zyuko22, Beric stabbing the Umber-boy-turned-wight with a flaming sword, lighting the spiral on fire, means that to defeat the White Walkers, someone will have to burn down the Grand Weirwood.
Let's go through that sentence one step at a time.
Who is Beric?
The most important thing you need to remember about Beric is he's died a whole bunch of times — six, to be exact. Each time, he was brought back to life by by Thoros of Myr's prayers to the Lord of Light, which is also how Jon Snow (Kit Harington) was previously resurrected. In the season 8 premiere, he, Tormund (Kristofer Hivju), and a gang of Brotherhood and Free Folk forces arrive at the Last Hearth (an abandoned House Umber castle), running into Eddison Tollett (Ben Crompton) and some of the Night's Watch. He is the one who identifies the pattern of limbs around the Umber boy as a message from the Night King, and also stabs the Umber boy with his flaming sword.
What about the Umber boy?
Ned Umber (Harry Grasby) was made head of House Umber after his father's death in the Battle Of The Bastards. While his father fought for House Bolton, in season 7 Ned pledges his loyalty to Jon Snow. In season 8, he's sent by Sansa (Sophie Turner) to the Last Hearth to round up his Bannermen and return to Winterfell, but his home is attacked by White Walkers and he is killed before he can complete the mission.
What is the flaming sword?
We first saw Beric's magic sword in season 3, when he used his own blood to light the sword in his battle with the Hound. Things were a little easier this time around, as Richard Dormer told Insider that the sword now lights using the Valyrian verbal command for "god's light" to ignite the flame, but he apparently also just needs to "think" the words, and it has the same effect. Regardless, you need fire to kill wights.
What's the significance of the spiral?
Here's where things get interesting. This is not the first time you've seen this spiral in Game Of Thrones — it's as symbol often left behind by White Walkers, and was also seen when the Children of the Forest first created White Walkers. The Children formed that very spiral shape and surrounded a man bound to a Weirwood tree and stabbed him with Dragonglass to turn him into the first White Walker.
As for what the symbol means, this is where zyuko22's theory comes in. Way back when, the Children of the Forest signed their peace treaty with the First Men in the middle of a grove of Weirwood trees — a grove that zyuko22 just so happens to think contains the the Grand Weirwood Tree.
What's the Grand Weirwood tree?
Great question. Zyuko22 believes the Grand Weirwood is pretty much the heart of all the magic in Westeros. The magical powers belonging to everyone from the Children of the Forest to the White Walkers to Bran Stark (Isaac Hempstead Wright) supposedly are rooted in the Grand Weirwood, so if Jon Snow or another hero figured out this connection, they could go find the Grand Weirwood and destroy it with fire, defeating the White Walkers.
Yes, unfortunately. You may have noticed that White Walkers weren't the only magical beings with ties to the Grand Weirwood, which means burning the tree could kill other things with magical connections...like Bran. This also puts Beric and Jon Snow in jeopardy, since they were brought back to life via magic, and maybe even the dragons, since they're magical as well.
Basically, it sounds like one of the only ways for Game Of Thrones to end is for someone to wipe out all the magic that's been plaguing the kingdoms, and the show may have foreshadowed just that on Sunday night. That would certainly make for a heartbreaking ending — but with Game Of Thrones, did we expect anything else?