Theon and Sansa, having survived the plummet from Winterfell's castle walls, run through the Wolfswood realizing there are already Bolton men with Ramsay’s vicious hounds chasing after them. Theon tries to hide their scent by crossing a river. Guiding a frightened Sansa, they make it across and hide by a fallen tree with Theon hugging Sansa to try to keep her warm. Hearing the dogs still after them, Theon urges Sansa to flee to the safety of her half-brother Jon Snow at Castle Black. Sansa, however, refuses to leave Theon behind to the Boltons. A group of Bolton men with the hounds find Theon, who has come out of hiding alone. Theon claims Sansa was hurt when they jumped and he left her to die, but the dogs quickly track her to the tree she hides behind. The leader mocks Theon over what Ramsay will do to him now and prepares to bring them back to Winterfell. Just as they are about to be arrested, Brienne of Tarth and her squire Podrick Payne arrive as a fight begins. Brienne kills most of them while a newly-trained Podrick manages to kill one himself. He is then attacked by another but Theon grabs a sword and kills the Bolton man. Although wary of anyone’s protection at this point, Sansa then accepts Brienne into her service after seeing Brienne’s skills as a fighter and remembering her sworn vow promised to Catelyn Stark.

Some time later, while making camp in the woods for the night, Theon and Podrick begin to prepare a fire while Brienne informs Sansa that her younger sister Arya Stark is still alive. She fills Sansa in on and encounter they shared in the Vale of Arryn several months ago. Brienne adds that she spent three days searching for Arya but was unable to find her. When Sansa asks how she looked Brienne comments that she looked well but wasn’t exactly dressed like a lady. With a smirk Sansa tells Brienne that she wouldn’t have expected Arya to be. Sansa is then reluctant to talk about her experiences under Ramsay Bolton's tyranny at Winterfell. She admits that she ought to have accepted Brienne’s help sooner as Brienne reassures her that it must have been a difficult decision to make. Meanwhile, Theon, wracked with guilt over his betrayal of the Stark family, then decides to leave the group and go home to Pyke instead of joining the Night's Watch. He informs Sansa that Brienne and Podrick will do a better job of looking after her, though he tearfully states that he would have gone with her all the way to Castle Black if necessary. He asks to take one of the horses with him, and the two tearfully embrace before parting ways.

Meanwhile, at Pyke, Yara Greyjoy reads a letter to her father Balon about how the Glovers retook 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, Yara tells the priest, Aeron Greyjoy, that she will find the person who did this and feed them to sharks while they're still alive. She 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. Yara argues that her father wanted her to rule, but Aeron says that he doesn't make the law.

Some weeks later, Theon finally returns home to Pyke, where he learns of the recent death of his father. Upon arrival his sister 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 as Reek years ago under Ramsay Bolton’s capture. She asks if he was let go, as Theon informs of his escape from Winterfell. 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 that she and their father received. 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 their father’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 Greyjoy 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 and of 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 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. 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 his brother 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, Theon and Yara 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, Theon and Yara 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. Lord 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 asserts that both of their fathers left the world worse than they found it, but they together are going to leave it better than they found it. Swayed by this, Yara affectively bends the knee for their new ruler. Meanwhile at Winterfell, Sansa and her loyal bannermen emerge victorious against House Bolton, as she and her half-brother Jon Snow retake their castle and kill Ramsay. Following this, out in the Narrow Sea, Daenerys’ three dragons soar above the combined armies of the Ironborn, Dothraki, Dornishmen, Reachmen and Unsullied. Theon and Yara stand on the deck of one of their Ironborn ships as they begin their voyage back towards Westeros to assist their new queen in taking the Seven Kingdoms.

Months later, following the long voyage back to Westeros, Theon and Yara join House Dorne and House Tyrell leaders at a war council in Daenerys’ ancestral home of Dragonstone. While Yara and Ellaria Sand firmly advocate an immediate assault on King's Landing, Lord 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 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. Yara and Theon then agree to take the Greyjoy fleet and escort Ellaria back to the Dornish capital of Sunspear in order to rally the Dornish forces and then ferry them up the coast to King's Landing.

Some time later, as they sail down to Dorne, Ellaria drinks Ironborn liquor with Yara, which she compares unfavorably to Dornish wine. She and Yara start to flirt with each other in front of Theon, as Ellaria then proposes that he take part in a threesome, to which Yara tells her to leave him be. As Yara and Ellaria began kissing each other, Yara's ship is suddenly struck. On the deck above, Theon and Yara discover that their fleet has been ambushed by Euron Greyjoy'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 of Dorne, fight fiercely but are overwhelmed by Euron's soldiers. Ellaria’s daughter Tyene Sand retreats below decks to protect her mother on Yara's orders, while her half-sisters Obara and Nymeria Sand fight against Euron's Ironborn. 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 Ironborn below deck, she and Ellaria are also overwhelmed. Ellaria tells Euron’s men to kill them quickly, but they are taken captive instead. With the entire fleet burning, Euron 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, Reek-like 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 his sister disappears into the night.

Over at Dragonstone, some time after the ambush, one of Queen Daenerys’ advisors, Lord Varys, informs her that the Ironborn and Dornish allies were attacked en route to Dorne in the Narrow Seas by Euron Greyjoy’s Iron Fleet. He adds that two to three ships have escaped, however, the rest have either sunk or have been captured. Varys then informs her that the Greyjoys, Ellaria and the Sand Snakes are all either dead or captured. Meanwhile, Theon is later 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 Daenerys.

During the time Theon sails back to Dragonstone, Lord Commander of the Night’s Watch and Theon’s childhood friend Jon Snow has arrived on the island to join Daenerys’ alliance. While Jon is on the causeway of the island, he and his advisor Ser Davos Seaworth see a lone Ironborn ship approaching, with Theon and some of the remaining Ironborn rowing to shore. As Theon disembarks, he is stunned to see Jon Snow, whom he had had last seen leaving Winterfell to join the Night's Watch several years ago. Since they last saw each other, Theon had betrayed House Stark, a factor that nearly destroyed their house and played a hand in a chain of events that contributed to the deaths of two of Jon's half-brothers, Robb and young Rickon. Jon is stunned for a moment as well, as Theon walks up to him, asking if Sansa is all right. A furious Jon angrily grabs Theon by his coat and shakes him, recalling Theon's past treachery. Jon then informs Theon that what he did to save Sansa is the only reason that he is not killing him on the spot. He releases Theon. Visibly relieved, Theon then informs them that his uncle attacked their fleet and took Yara prisoner. He asserts that he’s returned to ask Daenerys' help in saving Yara. Jon begrudgingly tells him that Daenerys has just left the island with her dragons and the horde of Dothraki warriors to attack a Lannister army that have now decimated House Tyrell.

Some weeks later, Theon, Daenerys, Jon and the rest of their advisors sail into King’s Landing to parley with Queen Cersei Lannister. Jon’s motivation for forging an alliance with Daenerys is the same reason as to why they have agreed to the summit meeting with the treacherous Cersei: to warn all of Westeros of a much larger threat than their feuding wars for the Iron Throne. The threat of the White Walkers and their army of the dead who will soon breach the Wall and into the Seven Kingdoms. When the group arrives they are escorted to the Dragonpit where all of the various factions meet. Theon finds his uncle Euron alongside Queen Cersei as they exchange looks. Euron then tries to posture, threatening to kill Yara unless Theon yields to him Euron then derides Tyrion Lannister's dwarfism. Theon and Lord Tyrion both retort to his taunts with their own. Once the meeting is on track, Daenerys and Jon attempt to warn Cersei of the greater threat coming for them all, but Cersei dismisses it as a ploy. To prove their claims, Jon Snow’s ally, Sandor "the Hound" Clegane, returns with the crate containing a captured wight that Jon and a hunting party retrieved from beyond the Wall. When Sandor kicks the crate over, the enraged wight spills out and launches itself out towards the nearest target - Cersei herself. Visibly horrified, Cersei and her allies recoil in horror as the Hound pulls the wight back on a chain and slices the creature in half. The assembled look on in shock as the wight's upper half still moves around. Jon then steps forward and picks up the wight's discarded hand and demonstrates how fire can be used to stop them. He then uses a dagger made of dragonglass to the heart, which finishes off the undead, bluntly stating that if they don't win the coming war such a fate awaits every person in Westeros. A horrified Ser Jaime Lannister asks how many wights are coming and Daenerys tells him the undead army number at least 100,000. Seemingly convinced, Cersei offers terms, however, she refuses to deal with Daenerys at all and calls upon Jon to keep the truce, requesting that he is to stay out of any future conflict between the two queens. Jon, however, says that he cannot serve them both - and reveals to all assembled that he has already bent the knee for Daenerys. With this news, Cersei then storms out, content to let the Starks and Targaryens battle the undead alone. After the meeting disperses, however, the queen’s brother Tyrion ultimately changes her mind as he meets with her in private. Cersei returns to the Dragonpit and agrees to work with Daenerys asthe Lannister army will march north to fight alongside them. Afterwards, Theon and Daenery’s contingent sail back towards the island of Dragonstone.

Some time after their arrival, Daenerys, Jon and their advisors discuss logistics as they plan their journey north. It will take the Dothraki horde a fortnight to ride north towards Winterfell, and the plan is to have Jon and the Unsullied soldiers cross the sea by ship and meet them at White Harbor.  Fearful of his Northmen’s reactions to their new alliance, Jon suggests that Daenerys ride with him instead of on dragonback so that the North can see her as a liberator and ally. After the meeting, Theon talks privately with Jon in the throne room. He informs Jon that even when they were growing up at Winterfell, Jon always seemed to know the right thing to do. Jon explains that he has made mistakes and has done things he regrets. Theon replies: "Not compared to me, you haven't," and confides that he has always felt torn between his Greyjoy heritage and his Stark upbringing. He adds that he tried to do the right thing, but was uncertain about the right step to take. Jon, still angry about Theon's betrayal against his family, asserts to him him that Lord Eddard was more a father to Theon than Balon Greyjoy ever was. However, Jon relents and tells Theon that he never lost Ned, as Eddard is a part of both of them. Jon concludes that Theon is both a Greyjoy and a Stark and insists that he can forgive for what is in his power to forgive. Theon confides that when he was Ramsay's prisoner, his sister Yara tried to save him, urging that he needs to save her now. Jon then encourages him to do so.

Afterwards, Theon returns to the remaining Ironborn on the beach, who continue to regard him with disgust. Theon declares Yara’s rescue mission, however, Harrag shuts him down, declaring Theon a coward, and proclaims that they 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 the late 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.

Some time after sailing to King’s Landing to save his sister Yara, Theon takes advantage of his uncle Euron's absence, who is inside the Red Keep castle with Queen Cersei. Theon and his small remaining 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, in their own ship, Yara informs Theon that she intends to sail back to the Iron Islands. She explains that with 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 the home islands while Euron is away. Despite this plan, Yara can tell that her brother wants her permission to leave in order to assist the Starks as they defend Winterfell against the impending invasion of the White Walkers and their army of the dead. Yara assures Theon that she will secure the Iron Islands as a fallback position for Queen Daenerys - as wights can't swim - and grants his request to leave. They embrace before Theon departs towards Winterfell.

Some time later, Theon arrives at Winterfell and waits with a detachment of Ironborn men in the Great Hall. When Daenerys and Sansa arrive, he informs the dragon queen that his sister Yara’s remaining ships could not be sailed to Winterfell and affectively will not be able to assist in the war. However, Theon then informs her of Yara's plans to reclaim the Iron Islands from Euron in her name. When Daenerys asks why he has not sailed home with his sister, Theon looks over to Sansa and asserts that he's come back to fight and defend Winterfell, if Lady Stark will have him. Sansa welcomes his return and emotionally embraces him. Afterwards, the sound of the horn brings Jon out into the courtyard as some of his allies bring bad news: the army of the dead should be arriving before daybreak. Jon then meets with all the prominent commanders to discuss strategy and notes that even with dragonglass, Valyrian steel and the defenses they have laid, they are still outnumbered. He suggests to make their leader, the Night King, the primary target- given that if he raised every monster in his army, they should all die with him. Bran Stark then interjects that he will come for him, as the Night King’s ultimate desire is to erase all memory of the world of men, something which Bran now possesses as the Three-Eyed Raven. Jon states they will place Bran in the crypts for his safety, but Bran refuses, declaring he'll wait in the godswood to lure the Night King out. Sansa and Arya Stark balk at the prospect of Bran using himself as bait, but Theon declares he and his men will defend Bran, as atonement for his previous capture of Winterfell. Jon then notes that the dragons will be held back until their enemy makes his move for Bran. Arya asks if dragonfire will kill wights, to which Bran can only reply he has no idea, as no one has ever tried it.

Late evening, some of the defenders are congregated together inside, conversing and drinking as a way to distract themselves from the coming battle. Brienne’s squire Podrick Payne starts singing softly. While he sings, various other defenders scattered in and around the castle also while away the evening as they wait for the horn to sound. Samwell Tarly, Gilly and her son are lying in bed together while Sansa is in the castle courtyard eating a bowl of soup with Theon. Arya Stark and Gendry Baratheon lie in bed after sleeping together, while Missandei gives Grey Worm a deep kiss goodbye, before he leads the Unsullied army towards the battlefield. Suddenly, a horn blast echoes throughout Winterfell, as Jon and Daenerys run upstairs to the ramparts, joining Lord Tyrion. The trio then witness the army of the dead standing in formation in the distance, and ready for battle.

Night has fallen at Winterfell and Bran is wheeled to the godswood by Theon and the Ironborn to wait as bait. On the battlefield, the united armies wait in ominous anticipation as Grey Worm readies the Unsullied army. From the blackened distance a Red Priestess named Melisandre arrives on horseback just in time to aid their army and magically lights a fire on each end of the Dothraki soldier’s weapons, as they then ride into battle and crash into the horde of wights. However, the Dothraki army is quickly decimated as the undead then rush down from the north and slam into the defenders around Winterfell like a tidal wave. Jon and Daenerys make strafing runs on the undead army with dragon fire but more keep coming and does little to affect their outnumbered defenses. Melisandre uses her powers again, this time to light the entire trench ringing Winterfell, as it bursts into flames. In the godswood, Theon can hear their approach and starts to apologize to Bran, but Bran politely cuts Theon off, saying that everything he did led him to where he is now: "Home". Theon is moved, but Bran must "leave" now as he wargs into a flock of ravens around Winterfell and witnesses the Night King psychically direct his army into a concentrated charge across the trenched flames, breaching the outer defenses. Thousands of them start swarming around the base of Winterfell's great stone walls, then climb over each other in a mass, using their strength to grip into stone. The siege takes another turn for the worse as the Night King uses his resurrection abilities to raise all of the defenders who died thus far into wights, and both Jon and Daenerys have been knocked off their dragons. As the castle is overrun, the wights infiltrate the godswood, as Theon and the Ironborn fire several arrows, but it does little to stop the onslaught. When the Night King eventually reaches the godswood with the rest of the White Walkers, Bran calls Theon a good man and thanks him, having finally redeemed himself. Knowing that there is no escaping death at this point, Theon chooses to die with dignity as his final act of atonement. He nods at the Night King, challenging him. The Night King steps forward and Theon charges at the him with a dragonglass spear. The Night King stops Theon and breaks his spear in half, then takes hold of the sharp end and stabs Theon through the stomach with it. Theon then falls to the ground, and bleeds to death as the Night King makes his approach towards Bran. When the Night King draws the sword sheathed on his back for the killing blow, Arya Stark suddenly appears and leaps at him from behind with a Valyrian steel dagger drawn. The Night King instantly reacts, spinning around to catch her by the throat and arm holding the dagger. However, Arya then drops the dagger into her free hand and drives the blade into the center of his chest, shattering him into ice, along with the rest of the White Walkers. With them destroyed, the entire undead army fall apart in and around Winterfell. As the Great War comes to an end, dawn finally breaks over the devastated castle. 

Following their victorious battle against the army of the dead, Winterfell has been cleared of the thousands of corpses in and around it. The fallen are then gathered into dozens of funeral pyres and Theon is mourned by Sansa, who places a pin with the insignia of House Stark on his chest piece, as a sign of gratitude and recognition of what Theon did for Sansa and her family since escaping their tormentor Ramsay Bolton. The survivors listen to Jon Snow give a eulogy as he informs that it is the duty of those who survived to keep them alive in memory for generations to come. Quoting the funeral speech used for members of the Night's Watch, he announces that they were the shields that guarded the realms of men, and they will never see their like again: “now their watch is ended.” The assembled leaders go forward with torches to light the pyres and say their final goodbyes to the heroic warriors who have helped prevent the destruction of humanity.

*In the aftermath of Theon’s death, follow Yara or Sansa’s journey throughout the rest of the series.