The Tenth and Fourteenth Doctor star David Tennant praises his successor Ncuti Gatwa’s performance in an interview for Variety
The Tenth and Fourteenth Doctor star David Tennant praises his successor Ncuti Gatwa’s performance in an interview for Variety
We don’t know yet.
David came back to play the Doctor for the 60th Anniversary, so we’re getting a story where regeneration went wonky. But it’s only temporary.
Basically, 13 regenerated into Tennant again (changing clothes this time in the process which is unusual), and the Doctor reacts with confusion. That was the new years special last December. The specials this year will have Tennant again and explain why 13 regenerated into a familiar face. After the specials, Gatwa takes over as the official new Doctor.
This seems to involve the celestial toymaker, who has the ability to alter reality.