Some months later, following Roose Bolton’s betrayal of the now-deceased Robb Stark during the Red Wedding massacre, it is revealed that Theon Greyjoy’s captor and subsequent tormentor is Bolton’s own bastard son, the sadistic Ramsay Snow. He had organized for Theon’s capture, promising Dagmer and the rest of Theon’s Ironborn men safe passage if they handed him over. However, Ramsay’s men instead flayed the Ironborn alive during the Sack of Winterfell, then burned the castle to the ground. Ramsay then sent false reports for his father Roose to deliver to Robb Stark which claimed that the Ironborn were responsible, as the Boltons were preparing to betray the Starks months before the Red Wedding. Ramsay sits in Theon’s dungeon inside the Dreadfort, the seat of House Bolton, as he eats his breakfast. He comments on Theon’s recently-castrated appendage and points to his sewn up and blood-stained trousers. Ramsay then taunts him by saying that girls that tried seducing Theon weren’t lying as he does have “a good size cock." As the mutilated Theon disturbingly witnesses Ramsay ingesting phallically-shaped food while laughing, Ramsay teasingly assures him that he is eating pork sausage. Ramsay then ponders if humans experience having a “phantom cock.” An exasperated Theon then begs for death as a release from the nightmare he’s endured for weeks on end. Ramsay informs Theon that this is not possible as he is more valuable alive than dead. Ramsay then notes that Theon reeks, and decides that this shall be his new name: “Reek.” Theon refuses to acknowledge the name, twice insisting that he is Theon Greyjoy, but after Ramsay beats him, he finally breaks down and says his name is Reek, avoiding further torture for the time being.

Shortly thereafter, at Pyke in the Iron Islands, Balon Greyjoy reads a message sent from Ramsay Snow while Yara cautiously opens a box crudely carved with the Greyjoy kraken sigil. In the letter, Ramsay explains the contents of the box as "Theon's favorite toy,” while Yara opens it to find her brother’s severed penis. The letter bluntly states that the Ironborn have until the full moon to withdraw from the North or receive more bits and pieces of Theon. In addition, any remaining Ironborn will be flayed alive. Despite the threat, Balon acts indifferent to Theon's situation since he defied Balon's orders and Yara's common sense. Furthermore, Balon callously assserts that Theon cannot further the Greyjoy line, as the contents of the box now prove. However, Yara does not share her father's attitude toward her last living brother. She announces her intention to take her fastest ship in the Iron Fleet, with her fifty best men, sail up the Narrow Sea and into the Weeping Water, besiege the Dreadfort, and liberate Theon from his captivity.

After sailing along the Narrow Sea for several weeks, Yara prepares her troops for their assault on the Dreadfort to rescue her brother from House Bolton. Out loud to her men, Yara reads the letter that Ramsay had sent her and her father Balon that came along with Theon’s mutilated penis. After reading the letter aloud, Yara then rallies her soldiers with an emotional speech. By nightfall, Yara and her troops then arrive at the Dreadfort and scale the walls of the castle. When they land, they quietly take out the guards as Yara learns of Theon's location in the dog kennels. There, the Ironborn and Yara find a traumatized Theon sitting in a cage. Yara opens the cage, but a terrified and delirious Theon refuses to go with her, believing it is another cruel trick that Ramsay has organized. Suddenly, Ramsay and several Bolton troops enter and a fight ensues, resulting in the deaths of several Bolton and Greyjoy soldiers alike. Theon hides from Yara and insists that his name is not Theon, then corrects her by repeating his name as “Reek”. When she tries pulling him out of the cage, Theon bites his sister. When Yara then witnesses Ramsay about to release his blood-thirsty hounds on her and the remaining Greyjoy soldiers, they are forced to quickly retreat from their rescue mission. After rushing back towards their ship, one of the Ironborn asks a devastated Yara about Theon, who informs him that Theon is "dead".

Two years later, in Pyke, Yara reads a letter to her father Balon about how the House Glover retook the castle of Deepwood Motte and killed all of the Ironborn who held the castle. Yara notes that their invasion is now a definite failure since Motte was the last stronghold that they held in the North. Balon insists that one of the reasons that the invasion wasn't successful was because Yara wasted men when she attempted to rescue her brother Theon. Yara continues to try to convince Balon to end the rebellion, however, Balon tells her that when she rules she can be content with their current standing, but for now she needs to obey his commands or he will make another heir who will. Afterwards, Balon starts walking on the swinging rope bridge that separates two of the towers of Pyke where he is surprised by the sudden return of his younger brother, Euron Greyjoy. Euron insists that Balon is too old to rule and it's now someone else's turn. Balon then tries to stab Euron, but Euron dodges the move and throws Balon off the rope bridge, who then plummets to his death. Some time later, at Balon's funeral on the shores of Pyke, Yara tells the Drowned Priest, Aeron Greyjoy, that she will find the person who did this and feed them to sharks while they're still alive. Yara swears to do this upon the Salt Throne, though Aeron explains to her that she isn't the ruler yet, because the law says that the Kingsmoot chooses the next ruler.

Some weeks later, after finally breaking free from Ramsay Bolton’s grip, Theon returns home to Pyke, where he learns of the recent death of his father. Upon arrival, Yara informs him that she didn’t believe the rumors of his return were true, as he’s been “dead a long time,” referring to his mental state under Ramsay’s capture. Yara states her unhappiness about his earlier refusal to leave the Dreadfort when she made an attempt to rescue him from Ramsay, adding that good men died trying to rescue him and that she risked everything for him. Theon continues to profusely apologise, as Yara becomes increasingly annoyed. Theon explains that Ramsay "broke him into a thousand pieces," which Yara affirms, "Yes, he sent us one of those pieces," referring to the box containing Theon's mutilated penis. Yara then suspects that Theon has returned home in order to declare himself King of the Iron Islands. Theon, however, insists that he doesn’t want the crown, adding the fact that he was not aware of Balon’s death until he arrived. When Theon starts sobbing, Yara rather violently grabs him by the shirt and shouts at him to look her in the eye. She demands her brother to tell her what he wants. Theon informs her that wants Yara to rule, and offers to help her in any way that he can.

Days later, Yara is the first to lay claim to the Salt Throne, however, an Ironborn man challenges Yara's candidacy on the grounds that she is a woman, as well as Theon’s return. Theon endorses his sister, urging the gathering to follow suit. Many shout for Yara to be their queen but before they crown her, their uncle Euron Greyjoy joins the gathering to lay claim himself. He openly mocks Theon for his military failures and emasculation before deriding Yara as a woman. To their surprise, Euron quickly admits to killing his brother, but defends his actions on the grounds that Balon was leading them to defeat in the North, which is met by resounding cheers from the crowd. Still campaigning, Yara then suggests building a massive fleet to make their mark on Westeros. In response, Euron announces that he also supports expanding the Ironborn fleet. Revealing a trick up his sleeve, he then proposes to marry the dragon queen, Daenerys Targaryen, and then carry her army and dragons back to Westeros from the eastern continent of Essos. The Ironborn support Euron's plan and declare him king. The Drowned Priest, Aeron, then leads Euron down to the sea to be drowned and reborn, as is custom in the Iron Islands. Knowing that Euron will kill them as soon as he is able, Yara, Theon, and many of their loyalists flee the Iron Islands during Euron's coronation, taking much of the Iron Fleet with them. After Euron revives himself, he is crowned by Aeron. After learning that his niece and nephew have fled with their best ships, Euron calls on his followers to build their own ships so that he may pursue the pair and kill them.

Some weeks later, Yara and Theon have sailed their contingent of the Iron Fleet across the Narrow Sea to the Free City of Volantis in order to rest before their continued journey east of Essos. Inside a brothel, Theon sits despondently, as Yara and the Ironborn men carouse with prostitutes. Yara repeatedly attempts to convince Theon to drink some ale, as he repeatedly refuses. Yara is persistent in coaxing Theon to regain his former identity and self- confidence, as she will need his assistance in getting justice and retaking the Iron Islands from their uncle  Euron. When pressed, he informs his sister that if justice were served, he would be burnt for his crimes, so she responds, “Fuck justice then. Do it for revenge.” Eventually Yara convinces him to put his guilt aside and assist her because she needs him. He drinks some ale and begins to gain some composure. She then reveals to Theon that she plans to take the Iron Fleet to a city named  Meereen and forge an alliance with Daenerys Targaryen before Euron does. After the sibling’s conversation, Yara departs to have sex with a female prostitute who has seduced her.

Some weeks after departing from Volantis, Yara and Theon arrive in Meereen to meet with Queen Daenerys and her new Hand, Tyrion Lannister. The Greyjoy siblings offer the dragon queen their fleet of a hundred manned ships if she will help them deal with their uncle and support their claim to the Iron Islands. Tyrion is wary of Theon, however, based on his crimes against House Stark. Theon then asserts that he has paid for what he has done. Daenerys agrees to support an independent kingdom of the Iron Islands, on the condition that the Ironborn will cease all raiding, reaving, pillaging and rape. Yara balks at this, as this is the Ironborn’s way of life, but Daenerys states that both of their fathers left the world worse than they found it. She then asserts that together they will leave it better than they found it. Swayed by this, Yara affectively bends the knee for her new ruler. Days later, out in the Narrow Sea, Daenerys’ three large dragons soar high above the Iron Fleet. Alongside them are the Dothraki, Dornishmen, Reachmen and Unsullied armies, who have all sided with Daenerys in the coming war. Theon and Yara stand on the deck of one of their ships as they begin their voyage back towards Westeros to assist their new queen in taking the Seven Kingdoms from the tyrant queen, Cersei Lannister.

Some time later, following the long voyage back to Westeros, Yara and Theon join the House Dorne and House Tyrell leaders at a war council in Daenerys’ ancestral home on the island of Dragonstone. Yara starts the council by urging to Daenerys that they have should immediately attack the capital of King's Landing due to their vast armada and Daenerys dragons, asserting that this would result in the capture of the city within a day. The Dornish leader, Ellaria Sand, firmly advocates an immediate assault as well, however, Tyrion advises against laying waste to the capital and causing the deaths of tens of thousands of innocents. Queen Daenerys insists that she doesn't wish to be known as the “Queen of the Ashes,” to which Lady Olenna Tyrell, having recently lost her family at the hands of Cersei Lannister, sarcastically ponders if Daenerys will take the Iron Throne by asking politely. Tyrion then proposes using a combination of Tyrell and Dornish forces to lay siege to King's Landing, much to the chagrin of Olenna and Ellaria, who balk at the thought of using their own soldiers. Tyrion, however, insists that using Daenerys’ Unsullied soldiers and Dothraki warriors would arouse the patriotism of Westerosi bannermen. Instead, the Unsullied will lay siege to the Lannister home of Casterly Rock. Yara and Theon then agree to take the Greyjoy fleet and escort Ellaria back to Dorne’s capital of Sunspear in order to rally the Dornish forces and then ferry them up the coast to the capital. Daenerys then requests a private audience with Olenna, stating her awareness of the fact that Olenna is only on her side due to their mutual hatred for Cersei. In response, Olenna encourages her to be “a dragon,” rather than a "sheep,” like the other high lords and ladies.

Later on, out on the Narrow Sea, Yara and Theon sail with the Iron Fleet alongside their Dornish allies: Ellaria Sand, her daughter Tyene, and Tyene's half-sisters Obara and Nymeria. In their quarters, the Sand Snakes are lying in bed and argue about killing Lannisters. Elsewhere, Ellaria drinks Ironborn liquor with Yara and Theon, which she compares unfavorably to Dornish wine. Ellaria asks Yara if she had ever been to Dorne, to which Yara responds that she has been there a few times. Ellaria responds that there is a boy in every port in Dorne and Yara tells her, "A boy, a girl. Depends on the port." As they begin to flirt with one another, and Ellaria motions for Theon to get her more wine, Yara explains Theon is not a servant but will be both her advisor and protector once she's killed her uncle. Ellaria then invites Theon to have a threesome with her and Yara, but Yara tells Ellaria to leave him be. While Yara and Ellaria begin kissing each other, the ship is suddenly struck. Racing to the deck above, Yara and Theon discover that their fleet has been ambushed by their uncle’s portion of the Iron Fleet. Euron's flagship rams into Yara's ship and lands a boarding party, with their uncle at the forefront of the attack. Yara and her men, along with the Sand Snakes, fight fiercely but are overwhelmed by Euron's soldiers. Ellaria’s daughter Tyene retreats below decks to protect her mother on Yara's orders, while Obara and Nymeria fight against Euron's men. Obara fights Euron, who quickly kills her by impaling her with her own spear. Nymeria then attacks him with her whip but Euron swiftly outmaneuvers her and strangles her to death with it. Though Tyene herself kills several of Euron’s men below deck, she and Ellaria are also overwhelmed and taken captive. With the entire fleet burning, Euron then captures Yara and then goads "little Theon" to come save her. Theon is about to come to his sister's aid, but he instead panics when Euron's men begin mutilating the wounded sailors, reminding him of the tortures he suffered at Ramsay Bolton's hands. To Yara's dismay, Theon quickly returns to his despondent and traumatized “Reek”-like mental state and jumps overboard while Euron laughs with cruel glee. Upon surfacing, Theon clings to floating driftwood, as Euron's fleet starts sailing towards King's Landing with his captives. Theon watches helplessly as their entire armada is decimated in flames and the ship carrying Yara disappears into the night.

Upon Euron Greyjoy’s arrival in King’s Landing, he victoriously parades Yara, Ellaria and Tyene through the streets of the capital. Yara and the Dornish women are pelted with rotten fruits and trash by the crowd, who take great delight in tormenting the prisoners. Euron mockingly tells his niece that they are receiving a hero's welcome. Once inside the Red Keep castle, as a token of his loyalty, Euron then throws Ellaria and Tyene in chains at the foot of the Iron Throne, occupied by Queen Cersei herself. Ellaria spits hatefully at Cersei's feet. As Euron stands next to the throne with the captive Sand women, Cersei proclaims Euron commander of her naval forces as well as assuring him of her hand in marriage once the war is won. While Ellaria and Tyene are left with Cersei to face her wrath for murdering her daughter Myrcella Baratheon, Yara is led away by armed guards. Meanwhile, Theon is rescued from being stranded out in the open Narrow Sea by one of the few surviving ships loyal to Yara. When their captain named Harrag questions him about his sister’s fate, Theon claims that he tried to save her. An unimpressed Harrag chides Theon, begrudgingly telling him that he would be dead if that were actually the truth. The remaining loyal Ironborn men then disperse from the deck, leaving a shattered Theon to pick himself up as they sail back to Dragonstone to plan their next course of action with Queen Daenerys.

Some time later, after returning to Dragonstone, the remaining Ironborn on the beach continue to regard Theon with disgust for abandoning his sister. However, Theon then declares a new rescue mission, but Harrag shuts him down, calling Theon a coward, and proclaiming that they instead are going to go where they can rape and pillage as they usually do. Theon reminds them that Yara has forbidden the Old Way, but Harrag threatens Theon and begins to assault him, telling him to stay down. Although he is knocked down, Theon barely reacts to the blows, as he has experienced far greater pain at the hands of Ramsay Bolton. He gets up to attack, but Harrag continues to beat Theon, again insisting that he stay or be killed. Theon once more defies him and attacks Harrag, who then grabs Theon and kicks him several times in the crotch. However, as Ramsay had previously castrated Theon, there are no testicles for Harrag to injure. Theon smiles as he gains the upper hand, smashing the captain's face practically to a pulp, and beating him into submission. The other Ironborn finally relent, accepting Theon and his mission. As they prepare to set sail to King’s Landing, Theon wades into the sea to wash his wounds in salt water, embracing his identity as an Ironborn.

In King’s Landing, Euron Greyjoy sails his Iron Fleet back to the capital, returning with the mercenary army known as the Golden Company. Queen Cersei is standing on the ramparts watching Euron's fleet ferry into the bay when her advisor Qyburn brings her the news that the Wall has been breached up north by the on-going threat of the White Walkers and their army of the dead. She coolly replies "good," as she walks back towards the Red Keep, resolute that her enemies up north can deal with them. Still a prisoner aboard her uncle’s ship, Yara asks Euron why he has not killed her, to which Euron sarcastically remarks upon their familial status as the last living Greyjoys, excluding Theon due to his castration. In addition, he states his preference of her company over his tongueless crewmen. Yara then rebuffs an offer of drink from her uncle, before stating that he has picked the losing side. However, Euron arrogantly states that he will simply leave Cersei should it come to that, but “will lay with her first.” Afterwards, in the throne room, Euron presents Cersei with the Golden Company's commander, Harry Strickland. After sailing to the capital himself, Theon takes advantage of his uncle Euron's absence, who is inside the Red Keep with Cersei. Theon and Yara’s small remaining Ironborn crew stage a sneak attack on Euron's ship. Using bows and arrows they silently pick off most of the guards, then Theon bursts into Yara's chamber with an axe and frees his sister form her restraints. She immediately headbutts him for letting her get captured in the first place, however, then embraces him, as they flee together. Afterwards, aboard their own ship, Yara informs Theon that she intends to sail back to the Iron Islands, explaining that the bulk of the Ironborn loyal to Euron are concentrated in the east with his fleet. As result, Yara has a chance to rally her remaining supporters to retake their home while Euron is away. Despite this plan, Yara can tell that her brother wants her permission to leave in order to assist House Stark as they defend Winterfell against the impending invasion of the army of the dead. Yara assures Theon that she will secure the Iron Islands as a fallback position for Queen Daenerys - as the dead can't swim - and grants his request to leave. Before they embrace, Yara tells Theon: “what is dead may never die.”

Some time later, Yara eventually recieves word of Theon’s death during the victorious Battle of Winterfell against the army of the dead. Subsequently, Daenerys then leads the Battle of King’s Landing, which ultimately results in the death of Cersei Lannister. However, no-longer worried with becoming “Queen of the Ashes,” a grief-stricken Daenerys, who recently lost two of her dragons as well as close advisors, decides to burn the entire city, innocent civilians included. With her tyrannical downward spiral, an imprisoned Tyrion Lannister convinces the King in the North, Jon Snow, to assassinate the dragon queen. Following this, Yara and the other leaders of the Great Houses of Westeros meet in the Dragonpit to discuss Jon and Tyrion’s punishment for their treason. Among them is Bran, the young Stark heir whose death had been faked by Theon. Jon himself is not in attendance, though Tyrion has been escorted to the trial. When Sansa Stark asks where Jon is, the Unsullied leader, Grey Worm, asserts that he decides what to do with their prisoners as the capital now belongs to the Targaryen forces. Sansa is not appeased, explaining there are thousands of Northmen outside the city gates and as result, harming Jon wouldn't be in Grey Worm's best interest. However, Grey Worm informs that there are also thousands of Unsullied soldiers as well. Yara herself sides with Grey Worm, as the Ironborn agreed to follow Daenerys, and wants Jon executed. However, Arya Stark warns Yara not to say another word about killing Jon or she'll cut her throat. Grey Worm asserts that his army needs justice for Daenerys' assassination and insists Jon cannot go free. Tyrion reminds him that he does not get to decide that, the power rests with their new king or queen. When it's pointed out there currently isn't one, Tyrion states that, as the most powerful lords and ladies gathered, they can elect one of themselves. Grey Worm eventually relents and tells the assembly to decide their new ruler. After some discussion, Tyrion is told that perhaps he wants the crown himself, though Tyrion disagrees as he is hated by half the people for serving Daenerys, and the other half for betraying her. When asked his opinion, Tyrion responds that “stories” is what unites people. Proposing an elective monarchy, he concludes, “There's nothing in the world more powerful than a good story… And who has a better story than Bran the Broken? A crippled boy who crossed the Wall and became the Three-Eyed Raven. He's all our memory. Who better to lead us to the future?" Sansa, however, expresses concern by mentioning the fact that Bran cannot father any children. Tyrion then asserts that this is good since sons of kings are often cruel. Tyrion asks Bran whether he will accept the crown, as Bran replies: "Why do you think I came all this way?" Tyrion waits for the reactions of the other leaders, as Yara and the rest all slowly start saying "aye" one by one. Representing the North, however, Sansa is still hesitant. She states her belief in Bran as a good king, but asserts that the North will once again be an independent kingdom, to which Bran agrees to. As punishment for his treason, Bran then appoints Tyrion as his new Hand, as he is to spend the rest of his life fixing his previous mistakes. With Yara and the other lords’ assent, King Bran is elected as the new ruler of the Six Kingdoms, marking the dawn of a new era.