As if a surprise Thirteenth Doctor cameo and Ncuti Gatwa’s unexpected departure weren’t big enough twists for the Doctor Who Season 15 finale, the episode ended with the Fifteenth Doctor regenerating into a form that looks like Billie Piper’s Rose Tyler. Why this happened will be answered when the next Doctor Who Christmas special airs on the 2026 TV schedule, but we may finally have a clue about its premise. If fans are reading into a recent blog post correctly, the special may be a throwback to one of the most popular episodes from David Tennant’s run as the Tenth Doctor.The Doctor Who website has a new post available to logged-in users (via IGN) that reads a UNIT report discussing the “Rose Tyler (2006 Cold case)” incident. This is referencing “Doomsday,” i.e. the Doctor Who revival’s Season 2 finale, where Rose Tyler, the Doctor’s companion at the time, was left stranded in another universe. Although Rose briefly reunited with the Tenth Doctor and teamed up with his allies at the time in Season 4, she ultimately returned to that other universe with the Metacrisis Doctor, a fully human clone of 10 with whom she could pursue a romantic relationship.
