The Doctor and Sarah Jane find themselves in a gravel pit. Sarah Jane finds a fossilised hand and removes a ring from it, placing it on her finger. She is knocked unconscious by a rock-breaking explosion and is taken to hospital. Possessed by an alien from Kastria, she takes the hand to Nunton Nuclear Power Station, where the hand re-grows a finger and begins to move!
The TARDIS arrives back on Earth but all is not as it seems as the Doctor and Sarah are attacked by mysterious space suited figures and discover that the dead are walking.
Eldrad reconfigures his body to its final, male form. Furious with finding his world dead, he states that he will return to Earth to rule it. The Doctor and Sarah Jane trip up Eldrad with the Doctor's scarf and he falls into a chasm and dies. Back in the TARDIS, the Doctor receives a telepathic message from the Gallifrey and sadly, leaves Sarah Jane on Earth after a hasty, unexpected goodbye.
The TARDIS lands on the old Dalek homeworld of Skaro where the Doctor and the newly regenerated Romana discover that someone is digging deep beneath the planet's surface.
The TARDIS takes the Doctor and Jo to a barren world in the far future where human colonists are scratching a living. But at night, the colonists are menaced by a monster.
