In King Renly Baratheon's tent in the Stormlands, the young king tells Lady Catelyn Stark that he and her son Robb would make natural allies. She begs him not to go to war with his brother Stannis, but Renly won't listen. As he asks Catelyn to take his terms to Robb, a shadowy cloud billows into the room. It coalesces into the shape of a man and plunges a dark blade through the king's chest; Lady Brienne of Tarth looks on screaming. Before anyone can react, the creature disappears and Renly's guards rush into the tent to attack Brienne, assuming she's the killer. She makes short work of the men and then collapses in tears across Renly's body. With no other choice, Brienne and Cat flee into the night.
The king's death throws the camp into disarray, and as Stannis' ships appear on the horizon, Littlefinger counsels Margaery and Loras Tyrell to flee while they still can. Loras agrees to postpone his revenge, and after he leaves, Margaery tells Littlefinger: "I want to be the queen."
In King's landing, Tyrion Lannister brings the news of Renly's death to his sister, Cersei Baratheon, who is drinking her way through the day. She's still angry with Tyrion for marrying Myrcella off, and she refuses to tell him what Joffrey has planned for the defense of King's Landing. Her cousin and lover Lancel Lannister, however, has been recruited as Tyrion's spy and tells the dwarf that Joffrey wants to launch pots of a mystical compound called "wildfire" from the city walls.
King Stannis Baratheon and his adviser Davos Seaworth walk through Renly's former camp. Stannis has recruited most of his dead brother's men and is ready to sail against King's Landing, but Davos begs him not to pursue his victory with witchcraft. "Loyal service means telling hard truths," Davos says, convincing Stannis to at least leave Melisandre behind when he launches his attack.
Tyrion walks the streets of King's Landing, where he hears a street performer refer to him as a "demon monkey." He meets with a man from the Alchemists' Guild, who explains that wildfire will melt wood, stone, steel ... and flesh. Holding a pot of the green substance, Tyrion asks how much of the weapon they've created, and the alchemist leads Tyrion to a room stacked from floor to ceiling with more than 7,000 jars of the substance.
Theon Greyjoy stands on the docks of Pyke, admiring his ship, but his crewmen aren't impressed with their new captain. One man outright threatens to mutiny and take the ship, but when Theon's sister Yara arrives and addresses the group, the men break into affectionate laughter. One of Theon's men, Dagmer, tells him, "They're not going to respect you until you prove yourself." This gives the young Greyjoy an idea.
Arya Stark serves food for Tywin Lannister and his bannermen at the haunted castle of Harrenhal. Tywin tells his commanders to stop waiting for Robb to fail and start finding a way to stop him, but none of the men have any ideas. Tywin picks up on the fact that Arya is from the North and asks her what she knows of Robb. "They call him the young wolf," she says. "They say he can't be killed." She leaves to fetch water for Tywin and finds Jaqen H'ghar, one of the prisoners Yoren kept in a cage. In exchange for Arya's saving his life, Jaqen offers her three deaths. "Speak three names," he tells her, "and a man will do the rest." She names the Mountain's torture master: the Tickler.
North of the Wall, the men of the Night's Watch trudge through the snow, waiting for the legendary ranger Qhorin Halfhand to meet them. They make camp at the Fist of the First Men, building up the ancient fortification to defend against wildlings. Qhorin arrives and tells Mormont and his men about Mance Rayder's massive army, "They'll hit us in force, and they won't run away when we hit back." Qhorin leads a small party - including Jon Snow -to take out Mance's lookouts.
Daenerys Targaryen and her handmaiden Irri play with one of her dragons in their new home of Qarth. Xaro Xhaon Daxos has sent her a dress, demonstrating his wealth, but Dany quips, "The last time a rich man gave me a dress, he was selling me to Khal Drogo." Still, she wears the garment and joins a gathering in the gardens, where she meets the warlock Pyat Pree, who creates an illusion and invites her to the House of the Undying. A masked woman warns Jorah to watch over Daenerys.
Catelyn and Brienne ride for Robb's camp, shaken by what they've seen. Brienne wants to return to kill Stannis, but Catelyn tells her it would be suicide. Instead, Brienne pledges to serve Catelyn. "I will give my life for yours, if it comes to that," she says.
Bran holds court at Winterfell, granting a farmer some orphaned boys to help tend his flock, when Ser Rodrik Cassel enters with news that Torrhen's Square has fallen under siege. Bran sends Rodrik and his remaining troops to fight off the invaders.
Xaro walks with Dany, asking her why she desires the Iron Throne. She replies that it's hers by rights and tells him that he's a conqueror, too - just less ambitious. He shows her his vault and claims that she could have enough to buy horses, ships and whatever is required to retake her homeland. "Marry me, and I'll give you the Seven Kingdoms," he says. Jorah is against the idea, but Dany is suspicious of the exiled knight's motivations. "You have a gentle heart," he tells her. "Make your own way. The allies we need are in Westeros."
As Gendry forges a sword in Harrenhal, he and Arya hear a scream and rush to the commotion. The Tickler lies dead in courtyard, and as Arya looks around, she spots Jaqen. She has dealt her first death, and she has two remaining.