Ncuti Gatwa stars as the legendary Time Lord in this special Christmas episode of the sci-fi adventure drama.

Ruby Sunday (Millie Gibson) was abandoned as a baby at a church on Ruby Road and has been looking for her birth parents ever since. When her adoptive mother Carla (Michelle Greenidge) receives a new foster baby who is then kidnapped by goblins, Ruby pursues them and meets the Doctor.

As they attempt to save the baby together, secrets from Ruby's mysterious past come to light.