Catelyn is riding south with twenty Winterfell guards, including Hallis and Shadd, and five lordlings, including Ser Wendel, Robin, Lucas Blackwood, and Ser Perwyn Frey, as an escort. She had not wanted to be the one to treat with Renly, but Robb convinced her there was no one else. Robb was preparing to march as she took her leave. The Riverlands were dangerous, but the war has not passed south of the Blackwater. As they ride, they soon encounter a scouting party led by Ser Colen of Greenpools. He tells her that Renly is camped near Bitterbridge, where the roseroad crosses the Mander, and that he will escort her there. As they get close to the Mander, the huge host becomes visible clustered around thousands of campfires. A great melee is being held next to the castle of Bitterbridge in front of a large crowd. As they ride up, a knight bearing the colors of House Tarth unhorses Red Ronnet Connington. Ser Colen tells Catelyn to have her men wait there, and he will present her to Renly. She notes some of his lords as she approaches the dais, including Lord Mathis Rowan, Lord Randyll Tarly, and Lady Arwyn Oakheart. At the center of them sits Renly with his new wife, Margaery. The melee is almost over now, with only four knights remaining. The Tarth knight quickly unhorses two of them, leaving the crowd favorite, Loras, as the final opponent. Loras almost finishes it, but the Tarth manages to turn the tide and defeat him. Catelyn asks Ser Colen who the knight is and is shocked to learn she is a woman, Brienne Tarth, daughter of Lord Selwyn. Renly declares her champion of the field of 116 knights and says he will give her any reward she asks. She asks to join his Rainbow Guard, he gives his assent. She is annointed Brienne the Blue. Ser Colen brings Catelyn forward. Renly says he will see justice done for Eddard. Lord Caswell has given Renly use of his castle, so he gives her use of his royal pavilion and offers her a place at the feast to be held that night.

That night, Catelyn is seated between Lord Mathis and Ser Jon Fossoway. Others at the feast include Brienne, Lord Willum and his sons, Josua and Elyas, Lord Steffon Varner, Lord Bryce Caron, Ser Robar Royce, Ser Guyard Morrigen the Green of the Rainbow Guard, Ser Mark Mullendore, and Ser Tanton Fossoway. Renly sits with Margaery on his left and Ser Loras on his right. Catelyn realizes that they are all so young and unblooded and labels them "the knights of summer." Renly bids her leave the hall with him. He asks if Ser Barristan had been sighted at Riverrun and is disappointed that he has disappeared.¹ He had been saving Brienne's spot on the Rainbow Guard for him. He takes her to the battlements of the castle to gaze out at his army. He says he has 80,000, with 10,000 more at Highgarden commanded by Lord Mace and a strong garrison at Storm's End. He will triumph. If Robb bends the knee and joins him, he can keep his titles, even King in the North, and rule as he pleases, but he must swear fealty. Catelyn mentions Stannis's right to the throne, and Renly counters that he would make an appalling king. Renly plans to win the throne as Robert won his, through force of arms. As they talk, a rider appears and calls for the king. Renly announces himself, and the rider declares that Storm's End is besieged by Stannis.