It's coming, and we all know it. One way or another, the Wall is coming down. Or maybe the Night King will circumvent it somehow. However it happens on Game of Thrones, the White Walkers will invade Westeros, and when they do, the real war — the conflict viewers have been waiting for from the very first episode — will finally begin.

So how do you bring down a gigantic Wall made of ice?

It's three hundred miles long and seven hundred feet high. Constructed 8,000 years before the events of Game of Thrones, it's believed to be made of not just ice but stone and earth, and likely built with the help of giants. Most importantly, legends tell that it's not just a physical barrier but a mystical one as well, embedded with very old magic to ward off the likes of the White Walkers, or "the Others," as they're known in George R.R. Martin's novels.

Fans have multiple theories on how the Wall could be breached, most of them entirely plausible. Potential spoilers are ahead, should any of these theories turn out to be true.

The Mark

Bran encounters the Night King on Game of Thrones

One of the most logical theories harkens back to the Season 6 episode, "The Door." That momentous episode had Bran Stark see a vision of the vast Army of the Dead, a vision that came to a startling end when the Night King saw Bran and grabbed his arm, placing a mark of ice on his skin.

Bran and his companions, Meera Reed and Hodor, had been living inside the Three-Eyed Raven's Weirwood cave, a place protected by various magical enchantments. The cave was located beyond the Wall, so those spells were all that kept the White Walkers from finding them. But once the Night King gave Bran his mark, the magical protection the cave provided was nullified. The Night King, the White Walkers, and their Army of the Dead soon appeared at the cave's threshold and were able to cross it easily.

So now that Bran has returned to Westeros, aka south of the Wall, wouldn't his presence render the Wall's magical protections moot as well? In other words, if Bran still has the Night King's mark on him, then logically speaking, he's carried that mark past the Wall now, so the dead should be able to pass beyond the Wall now. Right?

In theory, yes. There's just one snag: was the Night King's mark temporary or permanent? If it faded after the events at that cave, then the Wall's magic protections are in no danger. But if that mark is still on Bran...? That's a question that has yet to be answered.

The Horn

A mysterious horn from Game of Thrones

In the novels, there's a legend among the Free Folk north of the Wall about an ancient horn with magical qualities. It's called the Horn of Winter, or the Horn of Joramun, named after the ancient king north of the Wall who created it. The Free Folk believe that blowing this horn — which is said to be huge — will cause the whole thing to collapse.

The books tell that before he met Jon Snow, Mance Rayder put considerable effort into locating the Horn, but was never successful despite at least one claim to the contrary. Another contender was believed to be destroyed in a fire by none other than Melisandre (she really has a thing for burning stuff), but Tormund later expressed doubt that the horn burned by the Red Woman was the real Horn of Winter.

Obviously, there's a lot of uncertainty surrounding the Horn of Winter, not the least of which is the lack of a guarantee that it would work as advertised. Would blowing it bring the Wall down, or just leave the blower out of breath?

Also working against this one is the fact that the Horn of Winter/Joramun has never been mentioned by name on the show. Not once. A small, ancient horn was found by Sam Tarly with a cache of Dragonglass in the Season 2 episode, "The Prince of Winterfell." (That's it in the image above.) But it was quickly disregarded and it's unknown what became of it.

If the writers introduced the real Horn out of nowhere this late in the series, it just wouldn't ring true. Besides, the Game of Thrones gang may have already tipped their hand about the real plan...

The Vision

Sandor (The Hound) Clegane sees a vision in the flames on Game of Thrones

In the first episode of Season 7, "Dragonstone," Sandor "the Hound" Clegane looked into a fire and saw a vision of the dead invading Westeros by walking around the Wall atop the newly frozen-over body of water on the eastern edge of the Wall. This large body of water is called the Bay of Seals, and it's served as an effective extension of the Wall for millennia because White Walkers don't seem to like water.

But winter's here, and fans have already noticed that on the map seen in Game of Thrones' opening credits — which is often updated to reflect changes in the story — now shows the Bay of Seals to be frozen solid. Theoretically, this should give the Army of the Dead a convenient new hard surface to march across, circumventing the Wall altogether.

This possibility is given more credence by the vision that Clegane saw. And according to the law of Chekhov's Gun, a major plot point introduced in your story must be paid off at some point. Game of Thrones has been guilty of abandoning plot points in the past, so it's not entirely beholden to the strictures of standard storytelling.

But this one feels particularly important, especially given the detail and clarity that Clegane saw in his vision. Of the various methods listed here, the frozen Bay of Seals feels like the most likely to happen.

Other Possibilities

The Wall from Game of Thrones

Ice and fire. Fire and ice. Opposite forces that play an all-important role in GRRM's fantasy world. How about a more direct approach to the problem of the Wall. What would be the simplest and most obvious way to bring down a wall made of mostly ice? Fire, of course. It would take a great deal of fire, to be certain, but there just happens to be a source of limitless fire in Westeros. There are three of them, in fact: Daenerys' dragons. They could bring the Wall down simply by breathing on it. Granted, it would take a lot of breathing, but it could be done. The how and why one or more of the dragons would be involved in bringing down the Wall are anybody's guess, but anything's possible on Game of Thrones.

Some fans have theorized that Brandon Stark himself could somehow bring it down. He's gone all weird and emotionless now, so if he believed he was fulfilling some greater purpose stemming from his greenseer ability, it's not inconceivable that he could work some mojo on the Wall.

In the end, it's probably going to happen the way the Hound saw in his vision.

The eastern edge of the Wall was mentioned in that vision, but maybe you're wondering why the White Walkers don't just go around the Wall on the western side. What stops the dead from going around the Wall over there? Complex geography, that's what. Primarily, there's the Gorge, an insanely deep canyon that runs from the edge of the Wall all the way to the Bay of Ice at the coast. It's bordered to the north by the Frostfangs, steep, sharp-edged mountains of ice and stone. Wildlings have tried to traverse the Gorge and failed, though it's not impossible, thanks to the Bridge of Skulls. This high, narrow Bridge is considered so treacherous that only the most desperate would attempt to cross it. The Night King could certainly try to send his army around the Wall via the Bridge, but if he hasn't done it yet, it seems unlikely that he'll suddenly attempt it now.

However, there's something worth pointing out here. In the Hound's fiery vision, he mentioned there being a mountain where the dead were crossing past the edge of the Wall. He described this mountain as looking "like an arrow head." It's entirely possible this is an allusion to "the Mountain," his own brother, who Sandor longs to kill. But for a moment, consider the implications if it's literal. Check any canonical map of Westeros you can find; no mountains have been charted on the east edge of the Wall. But on the western edge are the aforementioned Frostfangs — any one of which has distinctly sharp, steep mountain peaks that... strongly resemble an arrow head.

What if the "eastern edge of the Wall" is a ruse? What if the Hound and the Brotherhood Without Banners travel there only to realize they're in the wrong place? What if the White Walkers breach the Wall on the western edge?

Game of Thrones has always loved a good fake-out. Is this another one? We'll find out soon enough.