Arriving in the Quarry

The TARDIS returns The Doctor, and his companion Sarah Jane Smith, back to present-day Earth. On exiting the TARDIS the time travellers find that the TARDIS has materialised in what appears to be a deserted quarry, silent except for the howl of a warning klaxon. Too late they realise that a nearby rock-face, in the quarry, has been set with explosives. Both The Doctor and Sarah find themselves buried under tons of rubble from the massive explosion.

The Doctor is thrown clear and he soon recovers as the quarry workers arrive on the scene. With their help The Doctor frantically searches for Sarah. Nearby Sarah regains consciousness to find herself entombed under the rocks. Seeing a hand in a gap in the rocks Sarah reaches for it thinking it is The Doctor’s But as she grasps it she is shocked to discover that is cold and hand. This makes her scream. As she does so some sort of energy moves from the fossilised hand into her mind, knocking her unconscious once more.

Sarah’s scream is heard by The Doctor. With help the rocks covering her are quickly pulled aside and the unconscious Sarah is taken to hospital where it is discovered that luckily nothing appears to be physically wrong with her. She eventually comes round and starts to act strangely. Sarah has come into contact with the last surviving fragment of a convicted criminal from the planet Kastrian, who was blown up in space as a punishment for attempting to wipe out his own people.

Assisting Sarah

Under the Kastrian’s control Sarah uses a blue-stoned ring from the fossil hand to stun Doctor Carter. In a trance Sarah then leaves the hospital taking the fossil hand with her and heads for the nearby Nunton Complex for Research and Development, where she enters the core of the nuclear reactor – setting off all the alarms.

But instead of killing her the fossilised hand soaks up all the deadly radiation and starts to rejuvenate. The Doctor arrives and manages to persuade the authorities to allow him to rescue Sarah. This he manages to do but as he carries the unconscious Sarah out of the reactor room he does not spot the Kastrian’s ring lying on the floor.

The Doctor Is Worried

Soon afterwards Sarah regains conscious again. But she is completely unaware of the recent events and all the trouble she has caused. The Doctor hypnotises Sarah and learns about the Kastrian’s influence over her – so proving that Sarah’s actions were not her own and were the result of an alien influence. The Doctor also learns of the Kastrian’s ring and the danger it poses to whoever comes into contact with it.

Meanwhile in the reactor room a technician discovers the ring. But before he receives The Doctor’s warning he comes under the Kastrian’s control. He places the fossilised hand into a highly radioactive storage compartment where it starts to come alive once more. The hand is discovered and a technician named Driscoll takes the hand back to the reactor core once more where unchecked the hand regenerates into a complete being – an alien female humanoid known as Eldrad.

Eldrad is a criminal who plotted to destroy Kastria when he was denied power. Eldrad disabled the spatial barriers which held back the solar winds, so that life on the surface became impossible. Caught and sentenced to death, Eldrad was placed in a Syllenic Obliteration Module - a space capsule - which was sent out into deep space. Before the last surviving Kastrians lost contact, the capsule was blown up. However Eldrad's hand was not totally destroyed and this part of the silicone-based body drifted to Earth where it lay for centuries – until Sarah discovered it when she was trapped in the quarry.

Breaking Into The Nunton Complex

Eldrad, who appears to all intents and purposes female - he patterned his regenerated body on Sarah's - persuades The Doctor to take him back to Kastria so he can reclaim his heritage. Unaware that Eldrad is a criminal The Doctor agrees to help the Kastrian and so The Doctor, Sarah and Eldrad depart in the TARDIS.

When they arrive on the planet Kastria they discovers that Eldrad’s heritage is a dead planet: the Kastrian race is long gone and the race banks of his people were destroyed by the last King, Rokon, and the Kastrian people in a final act of defiance in case Eldrad should ever return. He has his wish - he is King... But of nothing.

Furious, Eldrad, whose body has now been reconfigured into its proper form, tries to get The Doctor to return him to Earth so that he might rule there instead. Realising that Earth is now in danger The Doctor and Sarah manage to escape. But Eldrad storms after them. However, The Doctor and Sarah set a trap, using The Doctor's scarf, to trip him into a deep crevasse.

The Doctor and Sarah return to the TARDIS where, without warning, The Doctor receives a summons from Gallifrey. Realising that he cannot take Sarah there, as humans are not permitted on his home world, The Doctor redirects the TARDIS to Hillview Road, South Croydon, so Sarah can return to her home. However, after the TARDIS has gone, Sarah realises that she is not in Hillview Road and may not even be in South Croydon at all. She realises that she could be a long way from her home. She picks up her things and walks off, pausing only to glance up at the sky…