After three 60th anniversary specials celebrating the series' history, the new era of Doctor Who started properly with the first Christmas special to feature Ncuti Gatwa's Fifteenth Doctor and Millie Gibson's Ruby Sunday, "The Church on Ruby Road." The Christmas special introduced Ruby, an orphan found on the steps of a church on Christmas Eve, and saw her become entangled in an adventure with the Doctor. The Doctor and his new companion found themselves up against a horde of goblins, set upon eating babies and causing mayhem. The goblins were a more fantastical breed of villain than Doctor Who usually features, heralding things to come.
Source：https://www.cbr.com/doctor-who-christmas-special-new-science/
