When the TARDIS lands in a quarry on Earth, Sarah unearths what appears to be a fossilised hand, buried in one-hundred-fifty-million-year-old strata. Analysis shows the hand to be silicon-based and inert, but when Sarah begins to act as if possessed, the Doctor suspects that it may still be alive...
I wonder if anyone at the BBC ever had the presence of mind to just go and buy a quarry? The "Doctor" (Tom Baker) and "Sarah Jane" (Elisabeth Sladen) duly arrive amidst the rockfalls and amongst the rubble, she discovers a disconnected hand. It appears to be made of stone, and is wearing a ring which she promptly puts on her finger. Really? She ought to have known better as soon it takes control of her mind and drives her to find a nuclear plant where the hand can be rejuvenated by the radiation. With the "Doctor" hot on her trail, they soon discover that it's not just the hand that needs regeneration - and nothing the Earthlings can do will stop it. The "Doctor", though, remembers his "Janet and John" book of psychology and decides it might be better to reason with "Eldrad" (Judith Paris) and discover what it wants; why is she angry; what went wrong in her childhood? That kind of stuff. That takes them onto her home desolate planet where she has some scores to settle... Though she doesn't really feature so much, Paris proves to be quite a good glitter-clad alien and Sladen also does well, especially when she is reduced to an almost childlike state of hypnosis. There's a little room for a small tear in the eye at the end, too, and it ought to remind us Brits to take the security of our nuclear facilities just a little more seriously!