After The Doctor and his new companion Francis confronted the evil mummy pharoah king Badru (DW: Curse Of The Mummy) they go to the planet Skaro long before the daleks existed. They saw what it was like when there were a lot of Thal people and the daleks hadn't taken over everything. But on the planet Skaro they find out that there is an evil entity like a parasite that is influencing the thals to be evil. It is possessing them. The Doctor and Francis must find an ancient artifact called The Sacred Goblet Of Wisdom to return The Thals to their ordinary selves. But it was lost somewhere many centuries ago. It is hidden somewhere deep under the ground of planet Skaro. So The Doctor and Francis go deep underground. They begin a quest to search for The Sacred Goblet Of Wisdom but then the evil