Ser Harys Haigh is part of the force under the command of Roose Bolton that takes Harrenhal. The force hears Stannis Baratheon has been defeated at the Blackwater by Tywin Lannister and Mace Tyrell. At a war council between the Freys and Roose, Harys doubt's the young Robb Stark's chances against Tywin if Tywin can defeat the experienced commander Stannis. Later the Freys receive news that Robb has broken the marriage pact to marry a Frey.
The Freys agree to join Robb if his uncle Edmure Tully, lord of Riverrun, marries one of Walder Frey's daughters Roslin. Robb, his mother Catelyn, and much of his army are murdered when the Freys and Boltons betray them in what becomes known as the Red Wedding. During the massacre Harys wrestles a Vance and Black Walder Frey hamstrings them. Harys' father Ser Leslyn Haigh has part of his ear bitten of by the Greatjon.