The Doctor and Romana's search for the third piece of the Key to Time leads them to a stone circle in Cornwall where they find signs of strange activity and meet the inquisitive Professor Rumford who tells them of a nearby sect of druids.
On Earth to collect the third segment to the Key to Time, the Doctor and Romana encounter modern day druids in Cornwall making blood sacrifices to Cailleach, the goddess of war and magic, at a megalithic circle known as The Nine Travelers. The Tracer says the third segment is there, then says it isn't, which is very odd.—statmanjeff