Robb Stark shows his mother his plan to take Casterly Rock from the Lannisters. With so much at stake, he asks Catelyn for her advice; her instincts were right about Theon. Catelyn, grateful to have regained her son's trust, advises moving forward.
The Stark army arrives at the Twins and Robb, Talisa, Catelyn, Edmure and Blackfish are welcomed as guests by Lord Walder Frey. Robb apologizes profusely to Lord Frey and the women in his family for breaking his promise to marry one of them. Walder scoffs at the king's contrition and ogles Talisa. Despite the tense exchange, Walder pledges to put the past behind them.
The wildlings scout out a stone hut owned by a man who breeds horses for the Night's Watch. Orell, Tormund and Ygritte propose killing the man. When Jon Snow objects, suspicions arise. The wildlings race toward the hut, but Jon clanks his sword on a rock to alert the man, then distracts Ygritte mid-shot so she misses her target.
The Reeds, Bran, Rickon, Hodor and Osha take shelter from the downpour in an abandoned tower. The Reeds spot the fleeing horse breeder and the wildlings in pursuit. Hodor threatens to blow their cover when he shouts in panic, fearful of thunder. Reflexively, Bran's eyes flutter into the back of his head, immediately subduing the frantic giant.
Outside, the wildlings surround the old man. They task Jon with killing him as a test of loyalty. Because Jon hesitates, Ygritte ultimately does the deed. The wildlings realize the truth: Jon is still a crow. He's encircled by wildings and Tormund restrains Ygritte as a bloody fight ensues. With Jojen's encouragement, Bran wargs into one of the Stark direwolves and lunges to defend his brother. Orell wargs into his eagle right before Jon kills him. Shielding himself from the eagle, Jon rides off, abandoning Ygritte.
Daenerys Targaryen is counseled by Daario Naharis in her camp outside of Yunkai. He proposes her two best fighters enter the city with him through the back gate, so they can kill the guards and open the front gate for her army. Jorah is skeptical of Daario's intentions, but Grey Worm, making the decisions for the Unsullied, finds Daario trustworthy.
Moving forward with the plan, Daario leads Grey Worm and Jorah into the city. The three men fend off the Yunkish guards. A worried Dany paces until their successful return - aware of what happened in Astapor, the slave soldiers surrendered. Daario presents his queen with the flag of the city.
The Hound and Arya come upon a pork cart driver en route to the Twins. The Hound knocks the man out but reluctantly relents when Arya begs him not to him. As they approach the Stark camp, Arya is restless. The Hound calls her out - she's afraid they won't make it. Arya reveals that she knows his fear of fire, and promises to murder him one day.
Samwell Tarly forges a plan for him and Gilly: They'll head to the Nightfort where they can walk through a secret passage to the other side of the Wall. Gilly is impressed by Sam's knowledge and is awed to gaze upon the Wall.
Bran grasps the power of his gift when Jojen informs him that no other person can get inside a human's mind. Bran's commitment to find the three-eyed raven is affirmed. Aware that Castle Black might be under attack, he sends Rickon and Osha to Last Hearth to seek refuge with their bannermen, the Umbers. The youngest Stark is devastated to leave his brother, but Bran knows that Rickon's safety is paramount-if anything happens to him, his brother is the heir to Winterfell.
Edmure Tully is overjoyed when his bride is unveiled and he sees how attractive Roslin is. The two are married in the Faith of the Seven; a boisterous reception follows. Filled with drink, the Blackfish excuses himself. Once Edmure and Roslin are carried out as part of the traditional bedding ceremony, Black Walder closes the doors to the banquet hall and the band begins to play "The Rains of Castamere." Outside of the castle, the Hound and Arya are denied entrance into the celebration.
Lord Frey beckons Robb forward, and aware that something is amiss, Catelyn realizes that Lord Roose Bolton is wearing chain mail under his clothes. She calls out to Robb, but the massacre begins. Lothar Frey stabs Talisa repeatedly in the abdomen. Archers in the rafters rain arrows on the Stark attendees, wounding both Catelyn and Robb. The onslaught continues in the Stark camp outside. Arya watches the Frey men kill Robb's direwolf, Grey Wind. "It's too late," the Hound tells her before he knocks her unconscious and carries her away.
Catelyn uncovers a knife from the floor and grabs Lord Walder's wife from under a table. Now with a hostage, she begs for mercy, offering to forget and forgive everything so long as her firstborn is spared. Unmoved, Lord Walder shrugs and Catelyn looks on as Bolton stabs her son. Despairing, Cat kills the Frey girl and stands motionless with shock and grief until her own neck is cut.
Sam and Gilly arrive at the Wall. During a thunderstorm, Bran enters Hodor's mind to calm him down. Nearby, Jon refuses to kill an innocent man, so Tormund orders him killed. Bran uses his warg ability to save Jon, and Jon kills Orell then escapes, leaving a furious Ygritte behind. Osha, Rickon and his direwolf depart for the Last Hearth, while Bran and his remaining company plan to head beyond the Wall. Daenerys sends Jorah, Daario and Grey Worm to infiltrate Yunkai and open the city gate for her army. Yunkai soon falls to her forces. Robb arrives at the Twins and apologizes to Walder Frey, who feigns acceptance. Edmure marries Roslin Frey, but during the wedding feast, Walder Frey's men murder Catelyn, Talisa and most of the Stark bannermen, while Roose Bolton kills Robb. Arya also arrives at the Twins and witnesses a part of the massacre, but the Hound knocks her unconscious and carries her to safety.
Tarly, Gilly and her son arrive at the Wall. During a thunderstorm, Bran enters Hodor's mind to calm him down, an ability not possessed by any Wildling. Nearby, Snow refuses to kill a farmer, whom Ygritte kills before Snow is attacked by the other Wildlings. Bran uses his warg ability to save Snow, who kills Orell before escaping, leaving a furious Ygritte behind with chief Giantsbane. Osha, Rickon and his direwolf depart for the Last Hearth, while Bran and his remaining company plan to go beyond the Wall. Daenerys sends Mormont, Naharis and Grey Worm to infiltrate Yunkai and open the city gate for her army. Yunkai soon falls to her forces. Robb arrives at the Twins and apologizes to Walder, who feigns acceptance. Edmure marries Roslin and they leave to consummate their marriage before Walder's men murder Catelyn, Talisa and most of the Stark bannermen, while Bolton, revealed to be loyal to the Lannisters, kills Robb. Arya also arrives at the Twins and witnesses a part of the massacre, but Sandor knocks her unconscious and carries her to safety.
Robb lets Catelyn in on his plan to take Casterley Rock. In light of what happened when he went against her regarding Theon, he asks her advice. She tells them that it's a great risk but it's time to show the Lannisters how it feels to lose what they love. The wedding party finally arrives at Lord Walder Frey's bridge/castle, The Twins. Robb apologizes for spurning his daughters. Frey introduces him to all of the women he turned down for becoming queen. He apologizes to the many women directly and says he's sorry that he turned them down but he fell in love with Talisa. Frey calls Talisa forward and says it's not love for Robb but beauty. He ogles her and talks about what's under her dress and says he was betrayed for firm tits and a tight fit and he can respect that. Frey says it's time to party and put this mess behind them. Daario, Daenerys, Barristan, Jorah, and Grey Worm plot a plan to take Yunkai. Dany is clearly getting sweet on Daario. Jorah is skeptical but the others are convinced. And when she ask asks Grey Worm in the old tongue whether he trusts Daario, he says he does. Samwell explains to Gilly that they're heading for the Night Fort, the first castle on the wall. It has a secret sally port that he hopes to be able to find. Gilly wonders how he knows all of this and he says he read it in a book. She thinks he must be a wizard if he could divine all that information from "staring at marks on paper." She says her father used to tell her that no Wildling looked upon the wall and lived but here they are, alive. The Hound and Arya run into a hog farmer on the road on the way to the Twins. He helps the man fix his wagon, and then knocks him out. Arya asks him not to kill him, begs him and he grumpily acquiesces saying her kindness will get her killed someday. The man wakes and Arya knocks him out again. Bran, Rickon, Hodor and their crew reach a windmill in a tattered old village and wait out a storm. Hodor is freaked out by the thunder. Jon Snow and the Wildlings raid an elderly horse breeder's house. Jon asks Ygritte to spare the breeder yet she shoots and he manages to gets away anyway. The Hound taunts her saying the closer she gets the more frightened she becomes because she's afraid, now that she's so close she thinks she might not make it. She says she's seen fear in him too, fear around fire. He tells her to give it a shot and try to run. She says someday she's going to put a sword through his eye and out the back of his skull. She looks longingly across the river where her family is. The wildlings arrive near the ruined windmill after chasing the breeder. Hodor's yelling about the thunder is drawing the attention of the Wildlings outside until Bran uses his warg powers and goes inside him and causes him to pass out. The warg Orell in the Wildling party points out he heard shouting from the tower but no one seems to believe him. They capture the horse breeder. Tormund moves to kill the old man, but Orell tells him to have Jon do it instead, to prove his loyalty. Even at Ygritte's urging Jon is ultimately unable to kill the innocent man and Ygritte puts an arrow in his chest. Orell says Jon will always be a Crow and will stab him in the back he first chance he gets. The Wildlings attack him and Ygritte tries to help Jon but Tormund holds her back telling her not to die for a crow. Bran enters the minds of Summer and Shaggydog, his and Rickon's direwolves, and aides Jon, having the wolves attack the Wildlings. Jon kills Orell but not before being attacked by an eagle that Orell controlled using his warg abilities. Jon rides away leaving Ygritte behind. When night falls, Daario, Jorah, and Grey Worm arrive at the gate. Daario enters ahead of them, posing as a still loyal Second Son commander. Shortly after being let inside the city, he signals Jorah and Grey Worm to follow him. Once inside the city, they are ambushed by a group of Yunkai's slave soldiers, and though largely outnumbered, manage to kill them. More slave soldiers come through the doors and surround Daario, Jorah, and Grey Worm. At night, Walder walks his daughter Roslin down the aisle to her future husband Edmure Tully , who is pleasantly surprised by her beauty. Walder Frey shoots Robb a smirk. Edmure and Roslin are wed. Bran tells JoJen he was right, he can get inside anyone or animal he wants. JoJen says not anyone can get inside another person, that Bran is special. He tells them he saw Jon and that he got away. Osha wants to go to Castle Black and doesn't want to go north of the wall. Bran says she doesn't have to come. Bran asks Osha to take Rickon to Last Hearth, the home of the Umber family, Stark bannermen who will protect them. Rickon wants to stay with Bran but Bran says if something happens to him Rickon will be the heir to Winterfell. Osha reassures a tearful Rickon and she, Rickon, and Shaggydog depart. Osha tells them to keep Bran safe, that he means the world to her. After fighting a second wave of soldiers, the group returns to Daenerys, and tell her the attack on Yunkai was successful, and she is now in control of the city. Jorah stands proud before his Queen to inform her that the city is her's. However, Daenerys' main concern is for the well-being of Daario. Jorah's expression is one of heartbreak when he sees the look Daenerys gives the triumphant Daario.At the wedding feast, Bolton tells Catelyn that he also married a Frey, a grand daughter. He said he could have his pick and would give him her weight in silver. Catelyn states she hopes his wife makes him happy to which he replies his wife made him rich. Robb tells Talisa that Catelyn is starting to like her and Talisa says she feels the same but if she had her druthers she'd be back home playing her harp. Walder calls for the bedding ceremony to begin, and Roslin is carried off by the male guests, followed closely by Edmure, who is collected by the Frey women. Talisa thinks this is a very strange custom. He says it's tradition and gives proof of consummation. She says there are other ways and touches his hand to her belly. She says she wants to name him Eddard, after Robb's father. A new Ned Stark for Robb to raise. After they leave, Lothar Frey closes the banquet hall doors, and a musician begins playing "The Rains of Castamere," a Lannister victory song. Catelyn recognizes it and looks stricken. Using the food cart as their reason for being at the Twins, the Hound and Arya arrive at the wedding shortly after the bedding has begun, and are turned away at the gates. Soldiers begin running through the gates and Arya looks nervous. When the Hound moves to turn the cart around, he notices Arya has fled. Catelyn draws back Roose Bolton's sleeve to reveal that he's cloaked in chainmail underneath his wedding attire. She stands and slaps him and calls to Robb. Walder rises to make a toast to Robb, and signals his men to attack. Lothar draws a knife and repeatedly stabs the pregnant Talisa in the stomach, killing her and her unborn child inside of her. Before he can react, Robb is shot by the musicians with crossbows several times and falls to the ground. The soldiers attack all in the Stark party. Frey has a drink and very much enjoys watching the slaughter. Arya, having snuck past the gate guards, witnesses Frey men kill Stark soldiers and Grey Wind, Robb's direwolf. She is saved by the Hound, who knocks her unconscious before carrying her out of the castle. Catelyn, having been wounded by a crossbow bolt, holds a knife to the throat of Walder's young wife, demanding that Robb be allowed to leave. Walder says he'll find another wife, and takes another drink as Bolton betrays Robb, saying "the Lannisters send their regards" and stabbing him in the heart as he falls and dies next to Talisa. Catelyn cries out in anguish and cuts the throat of Walder Frey's young wife. She stands there, catatonic for a few moments as another Frey cuts her throat. She falls to floor, dead. Cut to black.