Terminus is the fourth serial of the 20th season of the British science fiction television series Doctor Who, which was originally broadcast in four twice-weekly parts on BBC1 from 15 to 23 February 1983.
In the serial, the alien time traveller the Fifth Doctor (Peter Davison) attempts to stop the fuel from a plague spaceship called Terminus from exploding and causing the destruction of the universe.
Terminus is the second of three loosely connected serials where the Black Guardian (Valentine Dyall) attempts to compel the alien Vislor Turlough (Mark Strickson) to kill the Doctor.
When the raiders' ship abandons Kari and Olvir, it becomes apparent that the spaceship is actually a transport carrying Lazars, sufferers of a leprosy-like disease, to a space station named Terminus.
The tank exploded, and the outrush of energy started "Event One" – the Big Bang – and hurled Terminus billions of years into the future.
Enlisting the Garm's help, the Doctor staves off the countdown long enough to disable the computer and cut the engine control wires.
Nyssa strikes a bargain with the Vanir – in exchange for synthesising hydromel and freeing them from the corporation's influence, they will turn Terminus from a leper colony into a true hospital, and with the Garm's help refine the radiation cure.
Deciding that her scientific skills are needed more on Terminus, Nyssa elects to stay behind, bidding her friends a tearful farewell.
Stephen Gallagher originally wanted to call Kari "Yoni" until Eric Saward pointed out that it was the Sanskrit word for the female reproductive organ.
A novelisation of this serial, written by Stephen Gallagher under the pseudonym "John Lydecker",[6] was published by Target Books in June 1983.