content: 
  ====''A Storm of Swords''====
  Catelyn's brother Edmure Tully places Catelyn under house arrest at Riverrun, but Robb pardons her after he announces his wedding to Jeyne Westerling, invalidating his marriage proposal to House Frey. Lord Walder Frey agrees to forgive Robb if Edmure marries his daughter Roslin, and Catelyn travels to the Frey seat of the Twins to attend the wedding with Robb and other northern lords. However, Walder Frey and his men take revenge on Robb for his slight on their house by slaughtering the northern host, an act of treachery that became known as the "Red Wedding". In an attempt to save her son's life, Catelyn takes Aegon Frey hostage and kills him when Roose Bolton kills Robb regardless, but she still has her throat slashed by Raymund Frey. Three days later, Catelyn is resurrected by Lord Beric Dondarrion, who sacrifices his life force to revive her. However, the period of time she spent deceased has caused Catelyn's body to decay; furthermore, upon her reanimation, she loses most of her previous personality, except for her hatred of House Frey. Catelyn then assumes command of Dondarrion's outlaw band, the Brotherhood Without Banners, and changes their aim to exterminating House Frey. Her uncompromising brutality earns her the moniker "Lady Stoneheart".