"Nothing happened. A sort of un-explosion has taken place."
IN THIS ONE... Eldrad lives! And she's a woman! The Doctor returns her to Kastria.
REVIEW: Britain's understanding of nuclear energy hasn't progressed very much since The Claws of Axos. Eldrad gobbles up a nuclear explosion, which makes Watson all aggro so he calls the military so they can nuke the power plant (no questions asked). And then they all hide behind a jeep waiting for the place to be leveled, except the Doctor, who knows (as I think the viewer does) that anything that can eat a nuclear explosion won't be phased by a couple of missiles (dessert!). So that's a scene that hasn't aged well, if it ever seemed reasonable at all. The Doctor takes the stance that Eldrad may be scared and lashing out, and wouldn't really be evil. Between his attempts at diplomacy and his propensity for distraction, the fourth Doctor is really acting like the third. Maybe Baker and Martin have never stopped writing for Pertwee. Certainly, Watson turns into a Pertwee guest star in this chapter, pulling a gun on Eldrad and refusing to listen to reason. Tom Baker does throw in his own mannerisms, wide smiles and inverted gestures, but he's not WRITTEN funny.
Instead, it's Sarah Jane who gets most of the comedy. Just the way she says "hi" to Eldrad is wonderful, so she does quite well with longer pieces of dialog. She gets a few sarcastic ones in - her reaction to seeing Kastria, for example - but her very best moment is the "I worry about you" exchange that sums up her relationship to the Doctor. Sarah believes SHE'S the hero of the story and that the Doctor is her responsibility, just as he seems to believe she is his. These characters are on an equal footing, he's her companion as much as she's his. This is a crucial point, because when that relationship is unbalanced by the Doctor refusing to acknowledge Sarah's misgivings about Eldrad - and she should know better than he does, Eldrad was in her head - it threatens their partnership. Or don't you know what happens in the next episode? There's a moment here when Sarah Jane just leaves the room and leaves the other two to it. It prefigures a more permanent departure.
So casting Eldrad as a woman - because he/she/it has copied Sarah's form - is quite a brilliant part of this theme! Eldrad is "the other woman", in a sense, someone as alien, as technically-minded, as potentially ruthless as the Doctor, but alike, not complementary as Sarah Jane is. Judith Paris makes a striking Eldrad too, with that glittering silicon skin and low, bassy voice. Obviously a villain, armed with a self-serving version of his/her/its life story (Eldrad is kind of the Omega of the Kastrian people, which should certainly strike a chord with the Doctor) and prone to megalomania, but she still retains a certain ambiguity. She reacts like a wounded animal, mistrustful of others, but somewhat gracious and able to reign it in and offer a grateful smile. I'm wondering if the Kastrians are in any way related to the Krotons, given both species' pointy crystalline heads. Kastrian bodies were created by Eldrad, apparently, but it's not like the Krotons look like they might have evolved normally. Cast-off experiments? I do take issue with Eldrad's massive powers though. It's not enough that she be an invulnerable energy vampire who can regenerate from near-total obliteration, she also has to have psionic powers, ESP, mind blasts and invasive telepathy! That's a lot. Or maybe the number of time she's shown using her reflective blue eyes as a lie detector just got on my nerves. Eldrad MUST know. Yeah, yeah...
THEORIES: This episode marks the first mention of "temporal grace", a dubious mechanism by which weapons don't work in the TARDIS because people don't really exist inside the TARDIS and so can't hurt each other. While that's an incredible concept that might tie into the machine's dimensions as mathematical construct (as per Logopolis), meaning that you might be digitized when you enter, the actual evidence points to the Doctor inventing this crazy idea out of whole cloth. Somehow, Eldrad's mental powers don't work, but we know the TARDIS has telepathic circuits, so these might be inhibiting Eldrad or bolstering the Doctor's own powers. Later, we'll see K9 and Cybermen shoot the place up, no problem. What's probably going on is the Doctor fast-talking Eldrad out of using her powers on him for longer. The intent was no doubt to sincerely make this a feature of the TARDIS, but future production teams ignored it, much as this episode seems to ignore the Time Lords' code of non-interference to claim they stop alien invasions in certain cases. Only the Doctor ever seems to adhere to this altruistic code, so maybe he's going by an older rulebook, and time being what it is, it's reasonable for Eldrad to know about the disused code.
REWATCHABILITY: Medium-High - Both Watson and Eldrad have some dodgy moments, but the Doctor and Sarah are rather wonderful, and in these, their last few minutes together, that's exactly what I want from the program.