Jon (Kit Harington) organizes the defense of the North. Cersei (Lena Headey) tries to even the odds. Daenerys (Emilia Clarke) comes home.
In the feast hall of the Twins, a very-much alive Walder Frey addresses the Frey men, toasting to their bravery at the Red Wedding and to the future of their house. The celebration takes a turn, however, when one by one the Frey men collapse from the poisoned wine. Arya Stark pulls off the face of Walder Frey and instructs Walder's young widow to, "Tell them winter came for House Frey" before leaving the corpse-strewn room.
Arya rides through the woods and comes across a group of young Lannister soldiers tasked with keeping the peace in the Riverlands. Arya warily accepts their offer of food and listens to them chat about missing their homes and families, all the while plotting how to kill them. When they ask why she's headed to King's Landing, Arya casually mentions she's going to kill the queen. After a moment's silence, the soldiers all burst into laughter. Arya soon joins in: Nobody is going to die here today.
In a vision, Bran watches the Night King leading his White Walkers and the massive Army of the Dead, comprised of wildlings, Night's Watchmen, Thenns, and even giants. Bran Stark emerges from warging as he and Meera Reed arrive at the tunnel through the Wall to Castle Black. Surprised by Bran's knowledge of his own personal history, Dolorous Edd raises the gate and allows the strangers to enter.
"I learned a great deal from her." - Sansa Stark
Jon Snow, the King in the North, addresses his lords in the Great Hall of Winterfell. He urges the houses to train everyone, regardless of age and gender, to fight the impending war, and asks every maester to scour records for mentions of dragonglass. Tormund agrees to have the Free Folk man the abandoned Night's Watch castles along the Wall, and volunteers to go to Eastwatch-by-the-Sea. The conversation turns tense when Sansa publicly disagrees with Jon's decision to allow the Umbers and Karstarks to keep their homes, but Jon holds fast to his decision, and young Ned Umber and Alys Karstark swear their loyalty. Sansa is displeased, and Littlefinger watches everything.
Afterwards, Jon tells Sansa not to undermine him in front of the other lords and ladies. Sansa counters that listening to her may be a wise idea. Maester Wolkan arrives with a message from Cersei: Bend the knee or suffer the consequences. Sansa warns her brother not to underestimate the Lannister queen.
Brienne of Tarth trains Podrick Payne in the Winterfell courtyard as the wildlings prepare to depart for Eastwatch-by-the-Sea. Lord Baelish approaches Sansa on the walkway and tells her he only wants her to be safe and happy. In no mood for Littlefinger's repartee, Sansa cuts him off as Brienne approaches. Brienne voices her concern that Littlefinger is only sticking around because he wants something, but Sansa knows exactly what Baelish wants.
"You think I listened to father for 40 years and learned nothing?" - Cersei Lannister
In the Red Keep, Jaime Lannister finds Cersei pacing a floor painted with a map of Westeros. Guessing Tyrion and Daenerys will land at Dragonstone, Jaime tries to convey the danger to House Lannister, but Cersei shrugs off his concerns.
Euron Greyjoy's ship, the Silence, sails into Blackwater Bay with the rest of the Iron Fleet. Jaime, disdainful of a Greyjoy alliance, wants to know how it benefits Euron. Cersei's answer surprises him: a queen.
Euron makes his case to Cersei as she sits on the Iron Throne, but she declines his proposal. Knowing she has little reason to trust him, the King of the Iron Islands promises to return with a priceless gift to prove his worthiness.
"It's where the Wall meets the sea. The waves are frozen.. There's a castle there." - The Hound
Beric Dondarrion, Thoros of Myr, the Hound and the rest of the Brotherhood Without Banners continue to make their way north. Seeking shelter from the wind and snow, they take refuge in an abandoned farmhouse. The Hound recognizes the home: he and Arya sheltered there before he stole his host's silver. Inside, the group finds the skeletons of the farmer and his daughter; Beric posits the pair was starving, and the father took their lives to end their suffering.
While eating, the Hound questions the Lord of Light's interest in Beric, but Dondarrion doesn't have an answer. Thoros suggests the Hound look into the flames of the hearth. The Hound objects at first, but curiosity gets the better of him. Carefully looking into the blaze, he is stunned to see a castle along the Wall, and the Army of the Dead marching past a mountain shaped like an arrowhead.
Thoros wakes up in the night to the sound of shoveling outside. He discovers the Hound burying the skeletons of the farmer and his little girl. Thoros grabs a shovel to help, and stays while the Hound stumbles through a prayer.
"Everyone in the Citadel doubts everything. It's their job." – Archmaester Ebrose
Wearing an acolyte's robes, Samwell Tarly trudges through his chores in the Citadel infirmary, scrub room, privy, mess hall, and library, where he eyes a gated section of restricted books. Later, while assisting Archmaester Ebrose with an autopsy, Sam requests access to the restricted section, hoping to find information to use against the White Walkers. Unlike other maesters, Ebrose believes Sam is telling the truth about what he's seen, but he denies Sam's request. With no other option, Sam steals a set of keys from a sleeping maester and slips several of the restricted books and scrolls into his bag.
In their shared room above an Oldtown tavern, Sam and Gilly pore through the books. Sam pauses on a page with a map of Dragonstone revealing a rich lode of dragonglass on the island. Sam immediately writes to Jon.
The following morning, Sam returns to his duties at the Citadel infirmary. A hand riddled with greyscale reaches for him from one of the cells. A voice - Ser Jorah Mormont's - asks if the Dragon Queen has come yet. Sam stutters he hasn't heard anything and scurries off.
Daenerys Targaryen, Tyrion Lannister, Missandei, Grey Worm and Varys approach her family's ancestral home of Dragonstone in a skiff. As her dragons fly overhead, Daenerys lands on Westerosi soil for the first time since she was an infant, and runs her hand through the sand of her birthplace. She enters the castle, tearing down the Baratheon banners left by Stannis, and passes through the audience chamber. Without saying a word, Tyrion follows her into the map room. The pair look over the abandoned table covered with ship and sigil pieces. Daenerys turns to her Hand and asks, "Shall we begin?"