"Fugitive of the Judoon" is the fifth episode of the 12th series of Doctor Who, and was first broadcast in January 2020. While the previous episodes were somewhat lackluster overall, this one was full of surprises, and there will be spoilers ahead:
The episode starts by introducing us to Ruth, a seemingly normal woman living in Gloucester, working as a tour guide. She is married to a man around her same age, named Lee, and just as we have established these things, and the normalness of it all, Gloucester is invaded by the Judoon, space cops that look like rhinoceros, who are searching for a "fugitive". The Doctor and The TARDIS detect this trouble and swoop down just in time to see what is going on. The Doctor intervenes, and meets Lee and Ruth, and tries to figure out what is going on. They seem to be normal humans, but are they? And just as she is puzzling that, one of her companions, Graham is kidnapped by a teleporter by...Captain Jack Harkness, who hasn't been seen on Doctor Who for over a decade. He mistakes Graham for the doctor and is surprised to find out that the Doctor is now a woman. And while we are figuring that out, The Doctor and Ruth are meeting in a cathredral, where Ruth, seemingly a normal middle-aged woman, manages to defeat a squad of Judoon using martial arts, and also is getting flashbacks to a lighthouse...
Okay, I am kind of breathless describing all of this! Which is the way Doctor Who is supposed to work! Even though parts of this episode had been spoiled to me in the past two years, I was still waiting in suspense. The episode managed to have action, even silly action with the rhino-like Judoon, and also have silent spots that made it seem more like a character drama.
At the lighthouse, The Doctor finds...a buried TARDIS. And Ruth finds a chameleon arch, which she breaks, revealing that she is... The Doctor. When the two Doctors meet, and start squabbling, they are astonished to find that neither remembers the other, this is seemingly a past incarnation of the Doctor, before the First Doctor. And meanwhile, Jack Harkness is telling the Doctor's assembled companions that they need to beware the "lone Cyberman". At the end of the episode, The Doctor and her companions share their astonishing revelations with each other, before they, and the audience, are interrupted by a distress call.
This episode managed to do two things: tell a story that was exciting, suspenseful, and well paced, while at the same time adding a big change to the Doctor Who mythology, letting current series runner Chris Chibnall put his own stamp on the mythology. But it didn't seem like it was forced, it seemed like it is a natural part of the growth of the shifting backstory of Doctor Who. The inclusion of John Barrowman's Jack Harkness felt the same way---not as a way to pander to the audience, but as a natural growth of Doctor Who mythology. The episode included an array of treats for the hardcore Doctor Who fan, while also remaining an accessible, fun episode.
There is one slight complaint I have, external to the story: while it is nice to have another female doctor, and a doctor of African descent (or at least her actress, Jo Martin, is, The Doctor herself is not human, of course), I felt it was added in somewhat hastily. The Doctor was, for a long time, a symbol of white, male, Britishness, and the sudden addition of the concept that the Doctor was non-white and female in the past seems to gloss over that tradition, without directly addressing it.