[Warning: This story contains spoilers for the sixth episode of Game of Thrones' seventh season, "Beyond the Wall."]

If death is indeed the enemy, then the enemy just scored a huge victory in the latest episode of Game of Thrones.

Season seven's penultimate installment, "Beyond the Wall," featured an action-packed battle scene between Daenerys Targaryen (Emilia Clarke) and her fire-breathing children bearing down upon the White Walkers, the first true collision of ice and fire in this epic narrative. While the Dragon Queen managed to save some lives and scorch some zombies in the process, she also sustained a devastating loss: Viserion, one of the three dragons, was brutally slain in the course of the battle, plucked out of the sky with a well-aimed throw of an ice lance from the Night King.

It gets worse: in the episode's closing moments, the Army of the Dead draped the dead dragon in chains, pulling its corpse out of the freezing water. The Night King sauntered up to the fallen beast, placed his hand upon its face, and brought it back to life. The final shot of the episode: Viserion's eye opening wide, icy blue in hue, just like everyone else in the White Walker army.

The Night King's forces required little assistance in their war effort against mankind, what with undead giants and bears on their side, not to mention the sheer quantity of corpses at their disposal. Now, with a dragon in their lineup, what's stopping the Army of the Dead from stomping all over the living?

For one thing, our heroes stand little chance in the immediate future. If Game of Thrones delivered one of the show's most simultaneously awe-inspiring and horrifying scenes earlier this season in the Loot Train Battle, which saw one of Dany's dragons ripping through Westeros for the first time ever, then the show is poised for an even more enthralling and chilling sequence in the near future. The Night King has a dragon now, and there's nothing to stop him from cruising right on into the Seven Kingdoms.

The Wall may be able to keep the White Walkers from directly invading Westeros, but the great barrier isn't so great as to keep a dragon-riding Night King from hopping the proverbial fence and unleashing unholy hell upon civilization as we know it. The Night King's victory in "Beyond the Wall" doesn't guarantee his victory in the grand scheme of things, but it virtually assures the fact that he will bring brutal destruction down upon at least one or more Westeros landmarks before the series ends — very bad news indeed for Winterfell, the nearest and most iconic stronghold in the North.

It also means we're all but assured a direct confrontation between two dragons, if not all three. For now, the Night King only has one winged beast on his side; there's no telling if he will be able to convert one of Rhaegal or Drogon to his cause before all is said and done. In any event, fans should expect to see an even more epic battle between ice and fire than the one featured in "Beyond the Wall," as the stage is set for violence between fire-breathing and ice-spewing dragons alike.

In terms of mythological importance, Viserion's death and resurrection answers one of the longest-running prophecies in Game of Thrones lore. It's long been said that "the dragon has three heads," an ominous phrase that seemed to suggest three different dragon-riders would somehow save the day. The identity of two of those riders has long been obvious: Jon Snow (Kit Harington) and Daenerys, both of whom have Targaryen blood coursing through their veins. But who would be the third rider?

Some theories pointed at Tyrion (Peter Dinklage), as he's been speculated to be a secret Targaryen himself. (Short version of a long-winded idea: Tyrion might be the son of the Mad King, not Tywin. More on how that would work, over here.) Such a twist might pan out in the books, but it's hard to see exactly how or why it would pan out on the show, given how often Game of Thrones tries to streamline George R.R. Martin's sprawling narrative, and especially now that the Night King has emerged as the third dragon rider — for now, at least.

There's still hope that one of our favorite characters can become "the third head," reversing these currently miserable fortunes: Bran Stark (Isaac Hempstead-Wright). When Bran first reached the Three Eyed Raven's cave in season four, the tree-dwelling mystic offered some foreboding words: "You will never walk again, Bran. But you will fly." Certainly, Bran has already soared high above the Seven Kingdoms, warging into ravens as recently as last week's episode, "Eastwatch." Now, the chances of Bran having to use his considerable powers to wrest control over Viserion away from the Night King are greater than ever. If the most magical Stark of the bunch is meant to protect mankind from the White Walkers, as we've been led to believe, then there's no greater way he can contribute than by slipping his consciousness into the husk of an undead dragon.

And what happens if Bran succeeds, or if the Night King loses control over his new steed through other means? Game of Thrones provided an answer in this very episode, in the form of Jon Snow killing a White Walker and watching as its minions died as a result. A few scenes later, a brainstorming session between Jon, Jorah Mormont (Iain Glen) and Beric Dondarrion (Richard Dormer) results in the theory that killing the Night King could lead to all of the wights dropping dead at once, since the White Walker commander is the one who brought them all to life in the first place. Imagine the scenario, then, in which the Night King loses control over Viserion, crashes into the snow below, and crashes again into Snow — Lord Snow, that is, wielding the Valyrian sword Longclaw. The end suddenly writes itself, doesn't it? 

Then again, this is Game of Thrones we're talking about the place where dragons only live for so long, and happy endings never come easily.

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