When Maddy discovers an old photograph of two little girls in her grandmother's belongings, she wants to know who they are. Nan reluctantly agrees to tell her the story, though she is unsure if Maddy is ready to hear it. The girls in the photo, Aggie and Mudgy, are two Kaska Dena sisters who lived many years ago in a remote village on the BC-Yukon border. Like countless Indigenous children, they were taken from their families at a young age to attend residential school, where they endured years of isolation and abuse. As Nan tells the story, Maddy asks many questions about Aggie and Mudgy's 1,600-kilometre journey by riverboat, mail truck, paddlewheeler, steamship, and train, from their home to Lejac Residential School in central BC. Nan patiently explains historical facts and geographical places of the story, helping Maddy understand Aggie and Mudgy's transitional world. Unlike many books on this subject, this story focuses on the journey to residential school rather than the experience of attending the school itself. It offers a glimpse into the act of being physically uprooted and transported far away from loved ones. Aggie and Mudgy captures the breakdown of family by the forces of colonialism, but also celebrates the survival and perseverance of the descendants of residential school survivors to reestablish the bonds of family.