|"You have to look without seeing, hear without listening. We're objects up there, living statues meant to serve."|
|— Walsh to Mare Barrow|
Walsh is the servant who arrives at the Barrow family's house, where she informs Mare Barrow that she has been summoned to the Hall of the Sun. Upon arrival, Walsh tells Mare that she has been given a job working as a servant in the kitchens.
Walsh tries to help Mare adjust to her new surroundings. She tells her to "say nothing, hear nothing, and speak to no one, for they will not speak to you." Cal later explains to Mare that he chose her to get Mare because she was from the Stilts like Mare is.
As a member of the Scarlet Guard, she helps pass messages from Farley to Mare while Mare is at the palace under the identity of Mareena Titanos. Walsh is also part of the Sun Shooting. She escapes with the other Guard members with the help of Mare and Julian Jacos.
Walsh is captured by Ptolemus, Cal, and the city guard. She was keeping watch in the old underground tunnels so Mare and Maven could get back safely from Naercey. Mare feels guilty for being the reason Walsh was captured. Before Elara can use her ability on her, Walsh swallows a suicide pill, saying, "For Tristan" before dying.
Mare describes Walsh as a playful and smiling young woman. She is unhappy with her job as a servant at the palace. She tells Mare that the job "starts to wear on you. We're objects up there, living statues meant to serve." As a member of the Scarlet Guard, Walsh was brave and loyal.
Walsh is described as having faded hair and tan skin, like most people from the Stilts.