Ncuti Gatwa appeared as the fifteenth Doctor in the last episode, opposite David Tennant as the 14th Doctor. The two Doctors worked together to defeat the Toymaker, who had first appeared in 1966. In the 14th Christmas Special, The Church on Ruby Road, Ruby Sunday (Millie Gibson) was an orphan abandoned on a church on Ruby Road in Manchester. She lives with her adoptive mother Carla Sunday (Michel Greenridge) and Grandmother Cherry Sunday (Angela Wynter). She is interviewed on television by real British reporter Davina McCall, where she expresses her hope of finding her real parents. Afterwards, she seems to have a string of bad luck. The Doctor (Ncuti Gatwa) starts to investigate.
Carla obtains a foster baby named Lulubelle and places a picture of her on her fridge with her other foster children. The child is kidnapped by Goblins. Chasing after them, she is aided by the Doctor, who has a pair of intelligent and powerful gloves which they use to climb to the Goblins’ flying ship. It seems the Goblins feed on coincidence and accidents and travel through Time to find babies to eat. They sing a song about it. When the King Goblin tries to eat Lulubelle, the Doctor and Ruby grab her and escape. A storm opens a crack in the ceiling and Ruby disappears. Carla changes into a different, not very nice woman. Neither Carla nor Cherry remember Ruby.
Realizing that the Goblins went back in time to kill Ruby, the Doctor goes after them. In the past, he witnesses the Goblins taking Ruby away. With the gloves, he pulls the ship onto the church steeple, impaling the Goblin King and making the ship disappear. He leaves Ruby on the church doorstep and sees a woman walk off into the night. Returning to the present, he tells Ruby what has happened, then leaves in the TARDIS to rescue Davina from being killed by the Goblins. Ruby follows him into the TARDIS, where she becomes the next companion.
The episode was directed by Mark Tonderai and written by our old friend Russell T. Davis. The Goblins all have different personalities and looks. The episode received 100% on Rotten Tomatoes. Gatwa was both charming and serious, which the Doctors have tended to be, though he was criticized for killing the Goblin King.