Capture of Winterfell

Theon Greyjoy built his plan in two moves. First he sent Dagmer Cleftjaw to lay siege to Torrhen's Square, noise meant to pull northern eyes elsewhere.

Ser Rodrik Cassel took the bait: he gathered what forces remained at Winterfell, some six hundred men, and marched out at speed, leaving the castle nearly empty. Meanwhile Theon, with only twenty men, cut through the heart of the region straight toward Winterfell.

Theon's best swimmers crossed the moat and scaled the walls with grappling hooks. They found the guard called Paunch stationed at the gate and killed him before he could raise the alarm.

With the gate open, the rest of the ironborn poured in and overran a garrison that had nothing left to fight with.

Theon declared himself Prince of Winterfell and took Bran and Rickon Stark hostage, along with Meera and Jojen Reed and the two Frey boys being fostered at the castle. He sent word to his sister Asha at Deepwood Motte asking for reinforcements.

But the Stark and Reed children slipped away, and rather than admit the loss to his own men, Theon had Ramsay Bolton — then disguised as Reek — kill two random boys in their place. Their heads, coated in tar, went up on Winterfell's walls as if they were Bran's and Rickon's.

News of the deaths reached Robb Stark on campaign, and grief pushed him toward Jeyne Westerling, whose family had been tending his wounded. He married her, breaking a promise to House Frey and forcing his own war plans to bend around the consequences.

It was a decision that would pull him back north and, down the line, into the Red Wedding.