Ruby Sunday was a companion of the Fifteenth Doctor. Abandoned as a baby by her mother, Ruby was soon fostered, and then adopted, by Carla Sunday and raised alongside other children that she fostered, developing a protective personality and changing the lives of Carla and her adopted grandmother, Cherry, for the better. Upon her nineteenth birthday, she and the Doctor defeated the Goblin King and his Goblins, preventing them from continuing to abduct the babies of the world. She then joined the Doctor in his travels, as things took an increasingly strange turn for her, both unsure of her origins before the night she was abandoned at the church on Ruby Road, and of the snow that followed her throughout space and time. Her travels with the Doctor soon culminated in Ruby finally being reunited with her birth mother. The Doctor left her with her family, promising that he would return for her.