少年As the Fifteenth Doctor, played by Ncuti Gatwa, takes over the TARDIS for his first epic adventure he will be joined by Ruby Sunday, played by Millie Gibson, as she makes her debut as the Doctor’s companion.The episode sees the Doctor come face-to-face with the mythical and mysterious goblins as his life collides with Ruby Sunday, played by Millie Gibson.Little is known about Ruby Sunday as she was abandoned on Christmas Eve as a baby. Now living with her mum, Carla and grandmother, Cherry her world is about to be turned upside when she encounters the Doctor and the two set off on their first adventure together