Adric suggests, twice, that the Doctor just use the TARDIS to leave the situation brewing, and is told, twice, that they can’t because the slave ship is full of slaves who don’t deserve to die.
What a punk!
But first, we have a problem. Rorvik honestly believes he can force the Doctor at gunpoint to get that slave ship out of there. Romana, she’s no dummy. She knows such things aren’t possible. And then K9 rolls in, and there’s one thing about the Doctor: he actually respects K9, even in his damaged condition, enough to listen to the robot dog warn the white void is collapsing.
See, it turns out bringing a ship made of dwarf star alloy, even if it is the only thing that can hold those Tharlis slaves, is a bad idea because that is what will make the void collapse. But having slaves is always a bad thing, and the Doctor disapproves of that. Is there a way out of there? Biroc promises to help through the mirror and everything…
But he doesn’t. And that is help.
In the meantime, Adric managed to swipe a laser cannon, and while Rorvik’s best idea is to simply blast the mirror, he doesn’t want to be blasted himself, so the Doctor, K9, and Romana can slip back to the TARDIS. And yes, there’s a comedic moment when Rorvik tries the cannon and just blows up the room with the mirror but not the mirror itself. Then he figures he can just use the slave ship’s afterburners, even though doing so is a really bad idea according to, well, any Time Lord that happens to be standing nearby. And no, Adric, the Doctor will not just leave because there are still slave prisoners on the slave ship.
By the way, there’s also a huge hole in that ship. That seems like trying to take off is a bad idea.
Never mind. The Doctor is going to have to go in and free the slaves, maybe sabotage the ship. He tells Romana to stay, but then she says they need two Time Lords so she says Adric has to stay using the exact same phrasing the Doctor said to her. So, she is learning.
But then a funny thing happens. Biroc and another of his kind sneak onto the slave ship. The other guy lets the slaves go, and Biroc tells the Doctor that they need to do…absolutely nothing.
And the Doctor gets it. He and Romana link up with Biroc and zap back to the TARDIS. But Romana isn’t getting onto the TARDIS because the Tharils need a Time Lord, and she can help them, and she didn’t want to go back to Gallifrey anyway. The Doctor gives her K9 because where she’s going, the dog will be fine, and such is the case. The TARDIS disappears while Romana and K9 enter the mirror world. There, she can use a replica of the TARDIS to rescue the rest of Biroc’s people, held as slaves all over the universe, and K9 can help her.
And the Doctor is stuck with Adric.
So, what to make of Romana and K9? K9 was, essentially, a silly character. I like silly. He was always as potent as the story needed him to be, and it was clear the showrunner who took over for this final season with the Fourth Doctor couldn’t stomach that. But Romana? First Romana may have known more than the Doctor in some respects, but he taught her to be more humane along the way. There was a time when Romana might have agreed with Adric and just dematerilized out of there, but now she’s going to be the Doctor (more or less) in another universe.
Still, it does feel a wee bit anticlimactic that she left the way she did. Sure, she grumbled about going back to Gallifrey, but in the end, that was about it and that was only here and there.
But apparently, Lalla Ward and John Leeson both repriced their roles for audio plays, where Romana did eventually return to Gallifrey and became President of the Time Lords. That’s…a lot more cool. I may have to track one of those down at some point.
But in the meantime, the Doctor has Adric. Maybe the Doctor can teach him a thing or two before he reaches the ultimate fate that I am already well aware Adric will suffer.