The first episode is called The Star Beast and sees the newly-regenerated Fourteenth Doctor (David Tennant) arriving on contemporary Earth, confused as hell as to why his new incarnation looks identical to his tenth. The Doctor is drawn into a conflict between the cute Beep the Meep and the monstrous Wrarth Warriors, who are pursuing the fluffball for reasons unknown. Also involved is the Doctor's former companion Donna Noble (Catherine Tate), her daughter Rose (Yasmin Finney) and grandfather Wilfred Mott (the late Bernard Cribbins, in his final Doctor Who appearance).
The second episode is called Wild Blue Yonder and sees the Doctor and Donna confront a mysterious showman (Neil Patrick Harris).
The third episode is called The Giggle and nobody is talking about that one. It's presumed that this episode will explain why the Fourteenth Doctor resembles the Tenth, and will see his regeneration into the Fifteenth Doctor (Ncuti Gatwa).
All three episodes are written by Russell T. Davies and directed by Rachel Talalay, Tom Kingsley and Chanya Button respectively.
We won't have to wait too long for more Doctor Who, either. The Fifteenth Doctor will get his first full outing in the Doctor Who Christmas Special (the first since 2017), presumed to be aired on Christmas Day this year, and then Series 14 proper, consisting of eight episodes, will follow in early 2024 and see the Fifteenth Doctor joined by new companion Ruby Sunday, to be played by Millie Gibson.