Battle of King's Landing

Daenerys had long been at odds with Cersei over the throne her family had lost generations before, and once the war against the White Walkers ended she picked that fight back up. Cersei, for her part, moved to shore up her position: she struck an alliance with Euron Greyjoy and bought the services of the Golden Company. When the attempt to parley between the two queens went nowhere, Daenerys's armies began marching on the city.

Before the assault, Tyrion asked Daenerys to hold back if the city's bells started ringing, since that would mean surrender. Cersei had the walls fortified, and Euron positioned the Iron Fleet in Blackwater Bay. That same dawn, Sandor Clegane and Arya Stark, who had ridden down from Winterfell by separate roads — he to kill the Mountain, she to kill Cersei — slipped inside the castle unseen.

Daenerys opened the battle with a move nobody in the city saw coming: she sent Drogon against Euron's Iron Fleet and wiped it off the water within minutes. With the sea cleared, her forces fell on the men Cersei had stationed along the walls and eventually broke down the city's gates.

Through those gates poured the northmen, the Unsullied and the Dothraki, who tore through what was left of the Lannister troops. From a window of the Red Keep, Cersei watched the scene and refused to accept she had lost. Meanwhile Jon, Davos and Grey Worm fought their way through the streets, while Daenerys kept flying Drogon over the city, knocking out one scorpion after another still mounted on the walls.

The Lannister soldiers eventually surrendered and the city's bells rang, just as Tyrion had foreseen. But Daenerys, overtaken by rage, chose to ignore the signal: she ordered Drogon to keep attacking, and the dragon began burning the city and killing people who were no longer fighting back. Grey Worm refused the surrender too, and the troops of the three allied houses turned to sacking King's Landing.

Jon tried to stop the slaughter, but his own men, blinded by hatred for the Lannisters, ignored him. Beneath the city, caches of wildfire went up and added to the destruction Drogon was already causing. Davos began getting out whatever civilians he could, and Jon ended up ordering his own forces to retreat.

Inside the Red Keep, which Daenerys and Drogon were tearing apart piece by piece, Arya and Sandor Clegane had reached the heart of the castle. There the Hound talked Arya out of the vengeance that had brought her south. He, on the other hand, did get his duel: he came face to face with his brother the Mountain, and the two killed each other.

Elsewhere in the castle, Euron Greyjoy crossed paths with Jaime Lannister; the fight ended with the Iron Fleet's captain dead, though Jaime came out of it badly wounded. He tried to flee with Cersei through the crypts, but the rubble sealed off the way out, and when the Red Keep collapsed on top of them, they died together.

When it was all over, Arya woke up among the rubble, covered in ash and blood, having failed to save anyone she had tried to. Around her were nothing but collapsed or burning buildings and streets full of bodies reduced to ash. Among the ruins she found, by sheer chance, Harry Strickland's horse, and rode it out of what was left of the city.

The casualties were beyond counting: between soldiers and civilians, the dead likely numbered in the hundreds of thousands, making that day one of the bloodiest in the history of Westeros. Drogon's fire had gutted entire districts, and in the days that followed so much ash fell over the city that it partly buried the dragon himself as he slept. Daenerys, now in control of what remained of King's Landing, ordered Grey Worm to execute the Lannister soldiers who had surrendered along with the rest of Cersei's supporters.

She then gathered the Unsullied and the Dothraki in the Red Keep's courtyard and addressed them from the castle's ruins, with Jon and Tyrion watching in silence. She called her troops "liberators," declared the sack of the city a success, and promoted Grey Worm to commander of all her forces. She closed the speech by announcing she meant to press on with her army, beyond Westeros itself.