It's a banner day on the TARDIS, and not because the Doctor and fam are cleaning up after deep space squid mating season. Graham has the sixth coupon from The Bandohzi Herald, which the coffee machine upstairs delivers regularly. That means they've earned a free holiday to a place called Tranquillity. Yaz thinks it a great notion because it will get the Doctor out of "her mood" (which we assume she's been in since seeing Gallifrey). But before the Doctor can protest, Graham's assembled the square coupons into a cube, which transports them all right off the TARDIS and off on vacay.
The Doctor: If I had crayons and half a can of spam, I could build *you* from scratch.
But, as with all Doctor Who vacations, this one is anything but tranquil. It's the most in-your-face soapboxing the show has done so far in the Chris Chibnall era, and the most pointedly angry about humans not evolving their behavior since Ten and Donna took a holiday on "Midnight."
At Tranquillity Spa, the fam all split up to find their rooms, see the amenities, or in Graham's case, sit down somewhere for three hours before getting up to sit somewhere else for three hours more. Between the four of them, everyone meets up with the cast of the week, from hostess Hyph3n (Amy Booth-Steel) to a lovely old couple of holidaymakers, Vilma (Julia Foster) and Benni (Col Farrell). Ryan accidentally contracts a Hopper virus from the vending machine, and, once he's gotten through the requisite experiences hallucinations of bats, meets Bella (Gia Re). Meanwhile, during what seems like a routine drill, Graham runs into a greehaired mechanic, Nev (James Buckley), and his far more intelligent son, Silas (Lewin Lloyd).
The Doctor tracks down Hyph3n with the Hopper virus in a crisp bag to demand some answers. There she meets Kane (Laura Fraser), who just sent Vorm (Will Austin), to hunt down what got in: a creature called a dreg. Hyph3n wants to transport everyone home, but it's compromised. The Doctor calls everyone to the "linen cupboard," which is the war room/armory against these dregs outside. Everyone makes it in but Benni. Oh, and Ryan and Bella, who are trapped in the steam room with a dreg ready to kill them. Thankfully, the Doctor rebuilds the ionic membrane that was supposed to be keeping these creatures out, and banishes them all.
Tranquillity, it turns out, isn't by the sea. It's a dome — this is what is known in the future as a "Fakacation." Built on a cheap planet, the Orphan 55 of the title, part of the reason why it's so low-rent is the local alien lifeforms. The dregs are deadly apex predators who survived nuclear winter when this world was first rendered uninhabitable and abandoned by its elites. Kane's built her business here because she sees potential in terraforming the whole planet, bankrolled by her Fakacation clients.
The dregs kidnap Benni in hopes of luring out their prey, and it works. The whole lot of them load up in a tank and roll out into the dead zone, where they start getting cut down, first with Hyph3n and Vorm, and then Benni, who Kane takes out in a mercy killing. But the dregs have always tried to get in and attack the guests, hence the ionic membrane shield. The membrane wouldn't have failed on its own, so this was sabotage. The Doctor hasn't had time to think it through, but she doesn't have to. Learning Kane killed Benni, the saboteur reveals herself: it's Bella, real name Trixabelle. She's Kane's daughter, and she's mad as hell that her mother abandoned her and her now-deceased father.
Bella is here to burn this place down, and Kane doesn't seem all that maternal about her daughter showing up, with both aiming guns at each other. But before anyone can shoot, a dreg attacks. Ryan saves Bella from it by throwing himself at her and launching them both into the transport. That uses it up, so the rest have to keep walking through the tunnels, filled with dregs nests, while the oxygen grows thin. The Doctor has decent control over the group — until they pass a sign that makes her stumble.
Yaz and Graham look up and are shocked to realize it's in Russian. This is, or once was a Siberian underground station. This is Earth. The dregs are humans, who adapted since various climate change and planetary disasters led to a nuclear holocaust. They are now carbon dioxide breathing oxygen providers: "Like a really angry tree."
And that's where the point of the episode takes over. Never mind the bombs (though Bella planted quite a few around the station), here's the real message. This is one of many possible futures, one where our leaders "sat at home arguing about the washing up while the house burned down." The Doctor already spent last week lecturing everyone on hope in the dark times, telling Ada Lovelace and Noor Inayat Khan that the fascists won't win, that even when it looks like the darkness will win out, people find the light. Now it seems that, at least in one timeline, that was all a lie. The elites of our planet took off in spaceships and kept the human race going elsewhere, while the rest of humanity — at least the ones who lived — became dregs.
It's a deliberately disturbing message in an unsettling episode, one where none of the cast makes it out alive, other than Team TARDIS and our green-haired mechanic and his boy. (I suppose seeing the cherubic Lloyd die already once in the last thirty days as Roger in His Dark Materials was enough.) It's as in-your-face message-y as the show has dared go in its whole history. But then again, in the 56 years of the show's existence, the crisis never reached such peaks as it has now. Will viewers listen? Or will we turn away from that final image of the dreg, and one possible, terrifying Fakacation of a future?