Monday's Doctor Who Christmas special marked the end of Peter Capaldi's role as the 12th Doctor, as well as Steven Moffat's seven years as head writer and showrunner for the iconic BBC sci-fi franchise about a time-traveling Time Lord, and it briefly introduced the 13th Doctor, Jodie Whittaker, a star of Broadchurch and now the first woman to play the Doctor. Capaldi's regeneration into Whittaker, 35, occurs at the end of the episode, and it appears the Doctor's time machine, the TARDIS, is not pleased with the change.
Whittaker will appear in her first full episode next year. Moffat's replacement is Chris Chibnall, the creator of Broadchurch — which, along with featuring the future 13th Doctor also starred the 10th Doctor, David Tennant.