When the 15th doctor played by Enkuti Gatwa takes over TARDIS for his first epic adventure, Ruby Sunday played by Millie Gibson will make his debut as a doctor's companion. In this episode, the doctor faces the mysterious fairy and his life conflicts with Ruby Sunday, played by Millie Gibson. People know very little about Ruby Sunday because she was abandoned before Christmas when she was still a baby. Cherry now lives with her mother, Carla, and grandmother. When she meets the doctor, her world is about to undergo a earth shattering change, and the two embark on their first adventure