Theon Greyjoy
Balon's last son, raised as Ned Stark's ward and Robb's sworn friend — a cocky, charming young man caught between the family that fathered him and the one that raised him.
A soul of House Greyjoy, born at Pyke.
The fuller tale
Season One
Ward of Winterfell since he was a boy, taken as a hostage after his father's rebellion and raised half a Stark without ever quite becoming one. He is glib, restless, and a little too pleased with himself, forever needling Jon Snow about his bastardy to cover for his own uncertain place in the household. He follows Robb south when the war starts, more sword than statesman, still working out which family he actually belongs to.
Season Two
Sent home to the Iron Islands to bring his father's fleet to Robb's cause, and finds only scorn — Balon wants no part of the war and no use for the son who left. Stinging from the rejection, Theon takes matters into his own hands and seizes Winterfell with a handful of ironborn while its garrison is away, a hollow conquest he cannot hold and does not know how to relinquish gracefully. He murders two miller's boys and passes their burned bodies off as Bran and Rickon to save face, then loses the castle anyway when Ramsay Snow arrives promising rescue.
Season Three
The rescue is a lie, and Ramsay Snow takes him apart for it, over long months in the Dreadfort's cellars that Theon experiences less as punishment than as a game whose rules keep changing — a door left open, a horse saddled and ready, freedom offered and then snatched back at the last possible moment, again and again, until he stops believing escape is a real thing that happens to real people. By the time the games stop he answers only to the name Reek, flinches from kindness as readily as cruelty, and has all but forgotten there was ever a Theon Greyjoy to go back to.
Season Four
Ramsay parades his creation like a hunting dog he trained himself, using him to talk the ironborn garrison at Moat Cailin into surrendering without a fight, then dressing him up as Theon Greyjoy once more to walk Sansa Stark down the aisle at Ramsay's own wedding — a performance of the boy he used to be, delivered by someone who no longer has any idea how to get back to being him. It is the closest thing to recognition Reek gets all year, and he flinches from it as if it were another order.
Season Five
Kept at heel in Winterfell through Ramsay's marriage and the cruelties that come with it, flinching at every order and offering none of the resistance the old Theon would have, until Sansa — trapped in the same house, with fewer options than he has — starts asking more of him than fear alone has left him able to give. When the moment finally comes he chooses her over the only safety he's known in years, and the two of them go off the castle wall together into the snow below rather than stay another night under Ramsay's roof.
Season Six
On the run north with Sansa through open country and worse weather, delivering her safely to Jon at Castle Black rather than peeling off toward any safety of his own — the debt from Winterfell finally paid in full. With that settled he sails home to the Iron Islands for the first time in years, arriving just as a kingsmoot convenes to choose a new ruler after their father's death. He has as strong a claim as anyone in the hall, and uses what's left of it to back his sister Yara instead of taking the crown for himself.
Season Seven
Yara's fleet is ambushed by their uncle Euron at sea, and Theon — the old panic taking over before he can stop it — abandons the fight rather than go down defending her ship, an old failure finding a fresh way to repeat itself. Yara is taken captive, and Theon spends the rest of the year at Dragonstone, useless and ashamed, trying to talk himself into being the man who goes back for her instead of the one who left her to Euron in the first place.
Season Eight
He does go back, leading ironborn fighters to free Yara from Euron's camp, then returns to Winterfell to make his peace with Sansa and stand for the family that once called him ward, hostage, and finally something like a son. In the battle for the living he holds the godswood at Bran's side against the dead until there is nothing left to hold it with.
How it ends for them
On the screen. Fell defending Bran at Winterfell (S8·E3)
The broken man came home to the godswood to pay for Winterfell with his life. Bran told him he was a good man — then Theon charged the Night King alone, and died a Stark's death in a Greyjoy's skin.
The show gives him the death the whole arc was aimed at. In the Long Night he holds Winterfell’s godswood with a handful of men, the last line before Bran, and empties his quiver into the dead until the Night King himself walks into the firelight. Bran gives him the only payment left worth having — “Theon. You’re a good man. Thank you.” — and Theon charges alone, spear leveled, at a being that has killed everything ever sent against it. The Night King snaps the spear aside and drives it through him. He dies in the castle he betrayed, defending the family he wronged, moments before Arya ends the creature that killed him.
No book counterpart exists yet: in the published volumes Theon has just been delivered out of Winterfell alive — shattered, frost-bitten, but himself again — and waits with Asha in Stannis’s camp for a battle Martin has not yet printed. Alive in the published books, with the hardest part of his story, by any telling, already behind him.
Their chapters, book by book
A Game of Thrones 1 chapter that name them
A Clash of Kings 6 chapters of their own, and 1 more that name them
A Dance with Dragons 7 chapters of their own, and 1 more that name them
Where the page and the screen part
The broad arc — betrayal, ruin, Reek, redemption — is shared, but the books tell the middle from inside his skull, and those chapters are among the most harrowing things Martin has written: the counting of fingers, the reflex of the false name, the slow theft of a self. The rescue plot differs materially — Jeyne Poole, not Sansa, is the bride he saves, smuggled off the battlements with the help of Mance Rayder’s spearwives — and so does the destination: book-Theon and his sister end the published volumes in Stannis Baratheon’s snowbound camp, his fate unwritten. Everything the show gave him afterward — the kingsmoot, the sea battles, the godswood — awaits whatever version the remaining books intend. In the published books, he is still alive.
Their journey
Where the two tellings send them to the same place the road runs whole; where they part, the screen keeps the left and the books the right.