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 regen...