The following contains spoilers for Doctor Who Season 12, Episodes 1,2 & 5.
For many Doctor Who fans, season twelve has been a return to form after season eleven's mostly lukewarm reception. When considering what works first we must acknowledge the well-written characters and plots backed up by Whittaker's stellar performance as the titular Doctor as well the performances of her entourage of often confused humans -- all of which helped to carry an uneven prior season. Thankfully, the show is now finding itself against by moving in a direction that is exactly opposite to the previous season. This is because Doctor Who season twelve's success stems from its leaning into its own wonderfully absurd and melodramatic mythology.
To understand what exactly this means it's important first to consider the issues that dragged season eleven down. Season eleven not only saw the introduction of a new doctor but it was also the first season with Chris Chibnall acting as showrunner. One of the main ways in which Chibnall tried to make his mark on the series was through focusing on new villains, and a more episodic style of story-telling. While the idea was admirable it resulted in a season that featured some strong historical episodes but failed to deliver some of the warm and familiar elements making the new Doctor feel like a reboot instead of a continuation.
In season twelve the writers have decided that instead of simply brandishing their machetes and hacking their way through entirely uncharted territory they are going to use the existing mythology to tell new stories. For long time fans, the outcome of this decision is nothing short of triumphant. This has served to revitalize a fan-base that was at best disappointed, and at worst utterly enraged. This was clear from the first episode forward, as it begins with a two-parter which not only acknowledges the series mythology but revels in it.
Doctor Who, Season 12, episodes one and two, Spyfall, come in as a two-part opener that feels much more like the two-part finales of Tenant and Smith's time with the character. Not only does it feature a mysterious and hitherto unheard of and entirely terrifying race of alien life forms making a bid for the entirety of the Earth, but it also revives The Doctor's longstanding rival The Master. The reveal comes toward the end of Spyfall part one and the twits don't stop there. While the master is posing as a Nazi officer in the course of his plan to turn all of Earth throughout history into billions of DNA hard drives, he tells the Doctor that Gallifrey has been destroyed again and that he was the one who did it. Not only that but he states that the Time Lords fundamental existence is a lie and that it all goes back to something called "The Timeless Child."
But the throwbacks and returns don't stop there. In the most recent episode, entitled Fugitive of the Judoon, we not only see the return of the space rhino police force but also the unkillable and always affable head of Torchwood and the (maybe) future Face of Boe, the one and only Jack Harkness. Jack returns but, in a clever writing move, doesn't actually interact with The Doctor, instead only interacting with her current companions Graham, Yaz, and Ryan. Captain Jack first appears as a voice from offscreen, causing fans to turn up the volume wondering if their ears are playing tricks on them and if wishful-hearing is a thing. But then he appears and says he knows he was missed and its good to be back. To add on to the ever-increasing pile of new plot threads for the old characters, Jack warns the new companions about the lone Cyber Man, before destabilizing and phasing out of the room again to leave Yaz, Grham, Ryan, and the fans scratching their heads about what exactly is going on.
This isn't to say that Chibnall is simply turning to the tried and true because he and his fellow writers are pushing forward with their own storylines, namely whatever is coming with the Lone Cyberman (not to mention Jo Martin's mysterious second Doctor) and the Timeless Child. Both of these are names that could potentially become as iconic for fans of the show as The Raggedy Doctor, The Girl Who Waited, The Impossible Girl, or Bad Wolf. While Chibnal has yet to deliver anything on the level of season 3's Blink, with the way things are looking for the franchise anything could be possible.