I don't know what I expected from this episode but what we got certainly wasn't it. And that's a good thing.
I greatly enjoyed seeing a full cast of well-developed characters with their own dynamics and histories quickly introduced and integrated seamlessly into the story. From the lovely couple of Gary and Mike, who naturally and coincidentally have exactly the necessary skills The Doctor needs to help save the day; to Cora and Len, with their fractured relationship once Cora's true heritage comes out; to Kid and Wynn, two justifiably angry survivors of a corporation-induced genocide and who nearly cause further deathly devastation on who they have deemed worthy of punishment; to poor Nina, the producer who is just trying to run a major song contest without everyone messing everything up with their vendettas. Woof, what a mouthful and I loved every bit of it.
There was a lot to unpack here, especially regarding the Hellion massacre and the resulting propaganda that ostracized the Hellias, all caused by a greedy corporation. For honey flavor. If the episode was longer (or even a two-parter), the story would've been able to dig deeper into those issues and how they affected Kid, Wynn, and Cora (and by connection, Len). As is, the episode did a good job of introducing those issues, if with only subsequent surface-deep thematic exploration.
On top of everything, we glimpsed once again the darker side of The Doctor. We've seen this from time to time, from The War Doctor to portions of The Sixth, Seventh, and Thirteenth Doctor's respective eras to The Tenth Doctor's memorable punishments for The Family of Blood. I especially reminded of the latter as The Fifteenth Doctor visibly and deliberately tortured Kid for his attempts to commit genocide. Undoubtedly, this will be a controversial moment in Doctor Who history but I think it's a good moment to explore.
The part that stood out the most to me is the very reason why The Doctor went this far: He thought Belinda was dead. Often times throughout the course of the show's history, but especially in the modern era, we've seen time and again companions indirectly and directly anchoring The Doctor towards good. Case in point, as soon as The Doctor discovers Belinda is actually alive, he suddenly sees what he has become and stops immediately, full of remorse. Again, with a longer episode, this theme could've been explored more deeply.
With so much to unpack on every level, I honestly believe that the brevity of the episode is the only thing that kept it from being truly excellent.
...and that's before we get to the episode's biggest bombshells:
At very long last, the triumphant return of Carole Ann Ford as Susan!!! After the terrible teases last season that Susan Twist was The Doctor's granddaughter, Susan finally returns in this episode as a recurring psychic message. Where and, perhaps more importantly, when is Susan contacting The Doctor from? How does she relate with the Gatwa era theme of reality? And is her return connected at all with the other bombshell...?
Also at long last, the return of The Rani! But wait, we got two for the price of one! As much as I still find the bi-generation, I do like having two Ranis running around and of course the newer one treats the predecessor as a subordinate. A more twisted version of a multi-Doctor relationship. I'm looking forward to watching Anita Dobson and Archie Panjabi embodying this duel role.
Speaking of Panjabi, I'm thrilled to see her as The Rani as I've been a big fan of hers for years. Come to think of it, didn't we hear rumblings and/or rumors that Panjabi was going to be on the show this season but we didn't know what role it would be? Or am I misremembering? Either way, I'm glad I was right that Dobson turned out to be The Rani all along.