'The Caves of Androzani' (4 Parts) Story Code '6R' by Robert Holmes

The Doctor and Peri arrive on the planet Androzani Minor, a world on which violent mudbursts occur whenever it reaches close proximity with its neighbouring planet of Androzani Major. Exploring the nearby cave system, the time travellers become exposed to a strange, cobweb-like substance; they then encounter a squad of soldiers, led by General Chellak and his second in command, Salateen, who mistake them for gun-runners and sentence them to be shot by a firing squad. The Doctor and Peri are rescued by the renegade Saharez Jek, who replaces them with android duplicates. Jek is a disfigured and insane scientist who has gained control over the only source of Spectrox, a life-prolonging elixir prepared from the guano of the giant bats that inhabit the lower depths of the caves. He maintains this monopoly with the use of his killer androids, and wants revenge on Morgus, the corrupt leader of Androzani Major's Sirius Corporation, who was once Jek's partner before he betrayed him. Engaged in a long-standing war with Chellak and his troops, who are financed by Morgus, Jek has now fallen madly in love with Peri, and plans to keep her and the Doctor with him forever. The two time travellers meet the real Salateen, also a prisoner of Jek, and whose android double is currently a spy in Chellak's camp. Salateen realises that the Doctor and Peri have contracted Spectrox Toxaemia, a fatal disease caused when they came into contact with the raw Spectrox earlier. Jek hands the Doctor over to the real gunrunners, who, unknown to Jek, are secretly employed by Morgus in an attempt to discover the location of the Spectrox. Slowly succumbing to the toxaemia, the Doctor manages to escape, and returns to Jek's base to rescue a terminally ill Peri. Morgus becomes paranoid, and suspects the President of duplicity. He murders him, and then travels to Androzani Minor to take charge of matters personally. He is appalled to find that his personal assistant has deposed him, and, together with the gunrunners, goes in pursuit of Jek in a final attempt to secure the Spectrox. The android Salateen leads Chellak and his men into a trap, and the troops are killed. As the molten mud from the planet core begins to erupt, Morgas and Jek confront and kill each other. The Doctor ventures into the cave depths to obtain milk from a Queen Bat, the cure to the toxaemia; he carries Peri into the TARDIS and makes her drink the cure, and then collapses. Peri looks on as the Doctor regenerates before her eyes...

Peter Davison (The Doctor), Nicola Bryant (Peri), Christopher Gable (Sharaz Jek), John Normington (Morgus), Robert Glenister (Salateen), Maurice Roëves (Stotz), Martin Cochrane (Chellak), Roy Holder (Krelper), Barbara Kinghorn (Timmin), David Neal (President), Colin Baker (The Doctor), Ian Staples (Soldier), Anthony Ainley (The Master), Matthew Waterhouse (Adric), Sarah Sutton (Nyssa), Janet Fielding (Tegan), Mark Strickson (Turlough), Gerald Flood (Voice of Kamelion)

Produced by John Nathan-Turner
Directed by Graeme Harper

TX:
Part 1 - 8th March, 1984 @ 6.40pm - 7.05pm
Part 2 - 9th March, 1984 @ 6.40pm - 7.05pm
Part 3 - 15th March, 1984 @ 6.40pm - 7.05pm
Part 4 - 16th March, 1984 @ 6.40pm - 7.05pm

Notes:
*Featuring the Fifth Doctor and Peri

*The end credit background sequence is changed, and features Colin Baker's face

*Working title: 'Chain Reaction'