A Game of ThronesEdit
Wylis is given command of the forces of House Manderly sent when Robb Stark calls the banners of the houses sworn to House Stark. He rides in the company of his brother, Ser Wendel Manderly, Lady Catelyn Stark and the knights Rodrik Cassel and Brynden Tully. Wylis remains with the Manderly men upon arrival at Moat Cailin, sending his brother to bring Catelyn before his liege lord.
Upon arrival in The Riverlands the Stark force stops at the Twins, where they are greeted by Ser Stevron Frey, the eldest son of Lord Walder Frey. Wylis insists that Lord Walder should have to leave his castle to negotiate terms with Robb. Wylis leads the Manderly forces under Lord Roose Bolton after the Northern force splits. He is captured at the Battle on the Green Fork by Lord Tywin Lannister.
A Clash of KingsEdit
Several offers are made by House Lannister to trade Wylis back to his father and his king. First Tywin offers Wylis back safely, provided that Wyman pulls all support for Robb. This offer is refused by Wyman. The new King's Hand, Tyrion Lannister, later offers the safe return of Wylis and Harrion Karstark in exchange for Willem Lannister.
Wylis is held prisoner at Harrenhal, and is mentioned to Arya Stark by Hot Pie, as he frequently visits the kitchens looking for leftover morsels. Wylis is freed from captivity when Harrenhal is taken by Roose Bolton, who kills Ser Amory Lorch, the previous castellan.
A Storm of SwordsEdit
Roose leads his force out of Harrenhal and back to the Twins, to attend the wedding of Lord Edmure Tully and Roslin Frey. Wylis is given command of the rearguard of Roose's force, and is taken prisoner after the men are attacked by Lannister forces under the command of Ser Gregor Clegane.
A Feast for CrowsEdit
A deal is struck between Wyman Manderly and Cersei Lannister, in which House Manderly will bend the knee to the crown and support Roose Bolton, and in exchange Wylis will be returned safely. A change is made to the deal when Cersei orders Wyman to execute Ser Davos Seaworth.
Cersei sends her brother, Ser Jaime Lannister, to Harrenhal to restore order and send Wylis back to his father. When he arrives Jaime is told of the slow death of Vargo Hoat, and how Vargo had been fed to the prisoners, who had been told it was roast goat. Wylis is brought before Jaime. He is sent to Maidenpool in a party consisting of members of the Brave Companions, Mountain's Men and under the command of Ronnet Connington.
A Dance with DragonsEdit
A feast is held by Wyman upon Wylis' arrival back at White Harbor. The feast is used as an opportunity for Wyman to talk with Davos Seaworth and Robett Glover about the plan to find Rickon Stark and make him the Lord of Winterfell.