In HBO’s “Game of Thrones,” Bran Stark has visions from throughout the history of Westeros, and several of those visions include a wildfire explosion within the walls of the city of King’s Landing. But to known history, that hasn’t happened, which indicates that Bran could have had a vision of the future in which Cersei burns King’s Landing with wildfire.
Let’s rewind for a second: The “Mad King” Aerys Targaryen instructed pyromancers to stash caches of wildfire throughout the underground streets in the city of King’s Landing. He wanted to “burn them all” — a phrase which, according to some theories, might also be related to Bran — and was obsessed with using a massive fire to essentially turn himself into a dragon.
But Jaime Lannister killed Aerys before the wildfire explosion occurred.
In Bran’s visions, we see Aerys screaming “burn them all!” We see the pryomancers creating the caches of wildfire. We see Jamie Lannister kill Aerys. And then we see a wildfire explosion.
In other words, the first three visions happened in the past. The fourth did not — so where did it come from?
Cersei’s history with wildfire in King’s Landing
Enter Cersei, the maniacal ex-queen who is locked in a battle for power with the High Sparrow. In “Game of Thrones” Season 6 Episode 6, Jaime Lannister tells Cersei he wants to kill the High Sparrow with his own sword. Cersei agrees that the High Sparrow must die, but instead asserts that Jaime/Cersei will have to be more subtle about their attack (i.e. not storming into his bedchamber and killing him with a sword). She also wants to display the impressive power of the Lannisters.
What if her power will be displayed through a massive explosion?
It wouldn’t be the first time Cersei used wildfire. In the books, at Tommen and Margaery’s wedding, Cersei burns a significant portion of the Tower of the Hand because she’s convinced her little brother Tyrion is hiding in the walls. She wants him dead, and uses the wildfire to smoke him out.
Theory: Cersei will use the wildfire in King’s Landing for a massive explosion
The theory is that Bran saw a vision of the future in which Cersei Lannister sets up a cache of wildfire under the Great Sept of Baelor. She somehow ignites the wildfire, which blows up the sept (and presumably the High Sparrow and his followers).
Dany will find King’s Landing amidst rubble from the explosion
It’s also possible that Cersei will go full crazy and blow up all or a significant portion of King’s Landing. There’s another vision Bran had in which it looks like King’s Landing is covered in smoke.
Additionally, in HBO’s “Game of Thrones” Season 2, Daenerys Targaryen sees a vision in the House of the Undying where she approaches the Iron Thrones amidst ash, snow and rubble. Could it be that that’s literally how she will see King’s Landing when she finally gets there?