The Space Pirates

From http://www.bbc.co.uk/doctorwho/classic/episodeguide:

The TARDIS materialises in Earth's future on a space beacon just before it is attacked by pirates. The travellers find themselves trapped in a sealed section of the beacon as it is blown apart and flown to where the pirates will plunder it of the precious mineral argonite. They then witness a conflict between the pirates and the Interstella Space Corps, led by General Hermack and Major Warne.

The ISC are convinced that the pirates' mastermind is an innocent yet eccentric space mining pioneer named Milo Clancey, while their true leader is a man named Caven. Caven has a secret base on the planet Ta and is assisted by Madeleine Issigri, daughter of his ex-partner Dom, who - unknown to her - is now his captive.

When Madeleine discovers Caven's full treachery she helps to bring him to justice. The time travellers are given a lift back to the TARDIS by Clancey in his rickety old ship, the LIZ 79.

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