While a storm lashes Dragonstone, Daenerys discusses the conquest of Westeros. Tyrion believes she can take the Iron Throne without a long and costly war, given their new alliances with House Tyrell of the Reach and Dorne. Daenerys thanks Varys for his help in this regard, but also uses the moment to question the Spider’s loyalty. Varys holds his own and pledges to always be honest with the queen. She in turn promises to burn him alive if he betrays her as he did his other rulers. Dany moves on to Tyrion, seeking assurance he will fight against and defeat his own siblings. Tyrion tells her he will find a way to convince her of his loyalty. Satisfied, Dany turns her attention to other matters – receiving the Red Priestess Melisandre.
Melisandre introduces herself and, in High Valyrian, informs Daenerys the Long Night is coming again and only the “prince who was promised” can save them. Daenerys counters she is not a prince – but Missandei corrects her translation; the word is genderless, and could refer to either a prince or princess. Less confident than she once was, Melisandre will not say whom she believes is promised, but knows both Daenerys and Jon Snow, the King in the North, have roles to play. Tyrion is surprised by the news of Jon’s rise to power, and suggests he would make a valuable ally. Daenerys tells Tyrion to invite Jon Snow to Dragonstone and bend the knee.
At Winterfell, Sansa, Jon and Davos discuss Tyrion's invitation. Both Sansa and Jon voice their belief Tyrion is a good man, but still think the invitation is too dangerous to accept. Davos agrees, but can’t help mentioning fire kills wights and Daenerys has dragons.
Queen Cersei speaks to a gathering of Westerosi noblemen including Randyll Tarly. She asserts the Mad King's daughter will be no better than her father, whose reign of terror they can't have forgotten. Randyll asks how she intends to fight three dragons; Qyburn cryptically answers they are working towards a solution.
When the meeting concludes, Jaime pulls Randyll and his son Dickon aside. Knowing the influence the Tarlys hold over the other houses, Jaime seeks to enlist Randyll to their side, reminding Randyll his liege -- Olenna Tyrell -- now fights alongside foreign Dothraki and eunuchs. Jaime then offers Randyll the title of Warden of the South in exchange for his loyalty.
Qyburn leads Cersei through a corridor beneath the Red Keep to the chamber where the skulls of the Targaryen dragons are kept. The queen lays her eyes on the largest of the skulls – that of Aegon the Conqueror’s dragon, Balerion the Dread. Having heard one of Daenerys’ dragons was injured by a spear in Meereen, proving they’re vulnerable, Qyburn reveals an enormous scorpion, a crossbow-like device with its steel-headed bolt aimed at the imposing skull. Pulling the lever to release the bolt, Cersei smiles as it smashes through the ancient bone.
Daenerys and her supporters continue to debate strategy. Firmly, but diplomatically, Daenerys says they will not risk many innocent lives by storming King’s Landing, but instead lay siege to the capital. Tyrion lays out the strategy: since using their foreign fighters – the Dothraki and Unsullied – would only hurt them in the eyes of the Westerosi lords, the Greyjoys will escort Ellaria to Dorne to collect her army and then, alongside the Tyrell forces, surround King’s Landing. Meanwhile, the Unsullied will assault Casterly Rock to take away the last refuge of House Lannister and deal a symbolic blow to Cersei’s cause. The group agrees to the plan, but Olenna, alone with Dany, instructs the young queen to consider listening less to the “clever men” around her, and embrace who she is: a dragon.
Missandel enters Grey Worm’s chamber, wondering why the soldier was not planning to say goodbye before heading to Casterly Rock. Grey Worm confesses it was too hard because Missandei is his weakness. He kisses her, surprising both of them. Missandei drops her gown, and gently undresses the self-conscious Grey Worm. Getting onto the bed, the two find other ways to express their love.
Inside a quarantine cell at the Citadel, Sam watches Archmaester Ebrose examine Jorah’s greyscale. Ebrose gives Jorah 10 to 20 years left to live, but only six months before his mind is overtaken. Speaking out of turn, Sam mentions Stannis Baratheon’s daughter Shireen was cured of the disease, but the Archmaester says Jorah’s situation has progressed well beyond their skill level. Sam is surprised to discover Jorah is the son of the late Lord Commander Mormont of the Night’s Watch.
Sam follows Ebrose through the library, helping collect books. He tells the Archmaester he believes he’s found a way to treat greyscale in a study of rare diseases. Ebrose, familiar with the procedure, ends the conversation by stating it is far too dangerous, and forbidden.
That night, Samwell returns to Jorah’s cell, explaining he was with Jeor Mormont when he died. Handing Jorah rum to drink and placing a leather bit into the knight’s mouth, Sam proceeds to use a scalpel and tweezers to peel away Jorah’s infected skin, and applies an ointment to the newly exposed area.
Arya eavesdrops on merchants in the Inn at the Crossroads until she’s surprised by Hot Pie, who asks if Brienne ever found her. She tells her old friend she is headed to King’s Landing, but is taken aback when Hot Pie reveals Jon Snow has retaken Winterfell from the Boltons. Outside, Arya weighs her options, and chooses to head north.
Arya makes camp in the woods, but is drawn to her feet by the sound of howling. A wolf pack slowly surrounds her, and its alpha steps into view. Arya locks eyes with the enormous creature and recognizes Nymeria. She asks her direwolf to return home to Winterfell with her, but understands when Nymeria steps back into the woods.
Maester Wolkan delivers a scroll to Jon, who calls a meeting of his northern allies. Jon shares the contents of this new message: Samwell Tarly has discovered Dragonstone sits on a mountain of dragonglass. He then reveals to the crowd he plans to accept Tyrion’s invitation to Dragonstone. Sansa protests he is abandoning his people, but Jon states only a king can persuade a queen, and he is leaving the North in good hands: hers.
Standing before Ned’s statue in the crypt, Jon is caught off guard when Littlefinger emerges from the shadows. Littlefinger swears he is not one of Jon’s enemies; he loves Sansa just as he once loved her mother. Jon grabs Littlefinger by the throat and issues a warning to stay away from his sister. Leaving the crypt, Jon waves goodbye to Sansa and rides off with Davos and several Stark soldiers.
Below deck on Yara’s ship, Theon watches uncomfortably as Yara and Ellaria flirt. They are interrupted by a sudden explosion, and the Greyjoy siblings rush on deck to discover their fleet under attack and their uncle Euron’s warship, the Silence, heading straight for them. Euron’s men storm aboard, outnumbering Yara’s men. Tyene runs to protect her mother below, while Obara and Nym take on Euron. He manages to disarm both women and kill them with their own weapons. His men seize Ellaria and Tyene from their compartment and drag them away.
Yara fights Euron, but he overpowers her. Holding his ax against Yara's throat, Euron taunts Theon, who stands frozen on the deck. To Euron's delight, Theon drops his sword and jumps overboard. Floating in the water, Theon watches as Yara’s fleet burns and the Silence sails off with his sister.
Daenerys sends the Dornishmen on Yara's fleet to Sunspear, the Unsullied to Casterly Rock and decides to not move on to King's Landing yet, intending to install a complete siege instead. She demands Varys to criticize her future mistakes instead of betraying her, which he did to previous monarchs. Melisandre arrives and tells her about the prophecy involving Daenerys and Jon. Grey Worm and Missandei consummate their relationship. Cersei gathers several lords, asking for their fealties and promising Randyll the title of Warden of the South. Qyburn shows Cersei an invented ballista for killing dragons. Arya meets with Hot Pie, who tells her of Jon's ascension to King in the North; she then decides to return to Winterfell. After receiving Samwell's letter, Jon leaves for Dragonstone in hopes of getting Daenerys's support against the White Walkers, leaving Sansa in charge and warning Littlefinger not to get close to her. Samwell begins a forbidden treatment for Jorah. Euron's fleet attacks Yara's. Obara and Nymeria are killed, while Ellaria, Tyene and Yara are captured. Theon flees the carnage in horror by jumping into the sea.
At Dragonstone, the Queen's council starts planning the invasion of Westeros. Daenerys sends the Dornishmen on the Greyjoy fleet to Sunspear, the Unsullied to Casterly Rock and decides to not move on to King's Landing yet, intending to install a siege instead. Grey Worm and Missandei declare their love for one another, which they consummate before Grey Worm leaves with the Unsullied. In King's Landing, Cersei has gathered many lords and insisted on fear for the Dragon Queen and why they should support the Lannister crown instead, promising Randyll Tarly the title of Warden of the South. In the Riverlands, Arya meets with Hot Pie, who tells her of Jon being named King in the North. She decides to return to Winterfell, and on the way she is briefly reunited with her former pet direwolf, Nymeria. At Winterfell, Jon Snow leaves for Dragonstone in hopes of getting support of Daenerys Targaryen against the threat of the White Walkers, leaving Sansa in charge. At the Citadel, Sam begins a forbidden treatment for Jorah Mormont's greyscale. Euron Greyjoy's Iron Fleet attacks Yara Greyjoy's, and in the battle, Obara and Nymeria Sand are killed, while Ellaria, Tyene and Yara are captured. Theon Greyjoy flees the carnage in horror by jumping into the sea.
A storm rages outside Dragonstone. Daenerys plans with Varys and Tyrion. Dany challenges Varys, gets him to admit he has been self-serving. Varys swears loyalty under threat.Red Witch Melisandre arrives, she states the prophecy of the Prince or Princess that Was Promised, and mentions Jon Snow the King of the North. Tyrion says he likes and trusts Jon, and can be a valuable ally. Daenerys orders a message for Snow to come and bend a knee.Sansa, Jon and Ser Davos review the message, Davos says it may be helpful.Cersei speaks to her Council instilling fear of the Dothraki hordes and the Targaeryon past. Her maester Qyburn says they are working on a plan for the dragons. Jaime speaks to Lord Tarly, he wants him to be their lead General, but Tarly is a Tyrell Bannerman.Jorah Mormont has bad grey scale over most of his torso, the Arch Maester says it is too late to stop it. Sam mentions Shireen Baratheon but the Maester says she was a child and it was caught early. Jorah can only stay in the Citadel one more day.Qyburn shows Cersei a crossbow weapon designed to kill the dragons, he points out they are not invincible.Daenerys has a war council; Olenna Tyrell, Yara Greyjoy and Ellaria Sand are there and encourage immediate war and attack. Tyrion explains the plan; Dorne and Tyrell armies will lay siege to Kings Landing, the Dothraki and Eunuch Unsullied will attack Casterly Rock the Lannister Home. Olenna tries to get Daenerys to 'be a dragon'.Missandei and Greyworm share a heartfelt farewell. They kiss, she disrobes, she strips him, they make love.Sam is given homework and is piled with reading. Sam says he may have found a cure for grayscale but the Arch Maester discounts it as too dangerous. Jorah writes a note in his room, is disturbed by Sam bringing food. Sam orders Jorah to drink a bottle of rum, he has the book and will follow the painful cure. Sam begins to cut off the infected tissue, Jorah is in agony.Ayra sits in a pub alone, a chubby lad, her old friend Hot Pie brings her a tasty bread. They chat, he reveals Jon Snow has won the Battle of the Bastards, surprised she finishes her meal and departs.Jon Snow gets Sam's message that dragonglass lies beneath Dragonstone. Snow then updates his Council and says he will travel to meet Daenerys, the North needs her dragonglass and power. Sansa and the Lords try to change his mind. Sansa will be left in charge, Petyr Baelish smiles at the news. Later Baelish talks to Jon in the catacombs, the two are not friends. Jon rides off with Davos and a small troop.Arya's horse is unsettled, she draws her sword as a pack of wolves surrounds her fire. The alpha is Nymeria, her long lost family pet. The huge direwolf turns and leaves with the pack.The Sand Snakes are unhappy on a ship. The Dornes are sailing with the Greyjoys. Suddenly they are under attack, Euron Greyjoy and his massive battleship ram and board, the fighting is fierce, the Greyjoy fleet is in flames. Euron kills two Sand Snakes, Ellaria is taken, then Euron subdues Yara; Theon, panics and jumps overboard. Later he surveys the ruined fleet on a float as Euron's ship sails away.