So, as often happens, there’s a scene in this episode that I couldn’t quite figure out. Between my bad hearing, British accents that sound a little muffled or warped, and other factors, the opening of this episode made no sense to me. That said, I think all I needed to know was an alien traitor was escaping, and the explosion that hit him or her had a slim chance of survival.
That seems to be about all I need to know.
Because, you know, a set-up like that means the alien traitor is still around. Even with the odds of one in three million. Otherwise, why bother introducing such a plot point?
Which brings us to the present. Or, at least, the present for when the show was under production. The TARDIS materializes in a quarry-like place. Sarah Jane is sure it isn’t South Croydon. The Doctor doesn’t know. What he clearly doesn’t know is the place is an archaeological dig or something. There are, like, explosives everywhere, and said bombs go off before the Doctor and Sarah Jane can get out. The Doctor is OK, but Sarah Jane is under some rocks. While the Doctor and some workmen dig her out, she touches a large stone hand. Said hand is missing a finger, but has a ring. Maybe that balances itself out.
Anyway, off to a hospital for Sarah Jane since she seems to be unconscious now. At least it isn’t the Doctor. But then a funny thing happens.
See, the Doctor and one Dr. Carter examine the hand because Sarah Jane won’t wake up. And the hand is…weird. An electron microscope shows it has a crystalline cellular structure. And while Carter thinks it could be a hoax, the Doctor isn’t sure. The Doctor goes back to the quarry to look for more pieces.
And while he’s out, Sarah Jane wakes up. But she doesn’t really say anything. Instead, it turns out she palmed that ring. She heads off down the hallway to get the hand back from Dr. Carter. And when he sees her, she zaps him with the ring. Down he goes…
Sealing the hand in a large Tupperware container, Sarah Jane leaves the hospital unopposed. She might have been had Carter woken up faster. Good news! That ring isn’t lethal! Bad news! It knocked Carter out for a good, long time.
Worse news! When the Doctor returns, he realizes the hand regrows cells in the presence of radiation. The cells in the electron microscope are already regrowing. And then the Doctor realizes there might be a nuclear plant nearby.
There is. Sarah Jane is walking there at a normal pace, and she still somehow gets there ahead of the Doctor, and he’s in a fast car. In fact, security stops the Doctor. Sarah Jane just ring-blasts anyone who asks her where she’s going.
That is, until she gets to a highly radioactive chamber and opens that Tupperware. And already, that hand regrew the missing finger and starts moving around…