Doctor Who - Season 20 - Eps 16: Terminus (4)
In attempting to reopen a doorway into the TARDIS, Turlough activates Terminus' automated fuel-jettisoning sequence. The first time this sequence was engaged, it flung its first of two massive loads of unstable fuel into the distant past, producing the Big Bang that created the universe. This second sequence - if the Doctor can't find a way to shut it down - will release a second massive load, the explosion of which will entirely negate the effects of the first.
About Doctor Who

Title: Doctor Who
First Air Date: 1963-11-23
Last Air Date: 1989-12-06
Status: Ended
Rating: 7.869/10 (from 666 votes)
Language: EN
Seasons: 27
Total Episodes: 694
Network: BBC One BBC Television
Genres: Drama, Action & Adventure, Sci-Fi & Fantasy
Production Companies: BBC
Synopsis
The adventures of The Doctor, a time-traveling humanoid alien known as a Time Lord. He explores the universe in his TARDIS, a sentient time-traveling spaceship. Its exterior appears as a blue British police box, which was a common sight in Britain in 1963 when the series first aired. Along with a succession of companions, The Doctor faces a variety of foes while working to save civilizations, help ordinary people, and right many wrongs.
Cast

Sylvester McCoy
The Doctor

Sophie Aldred
Ace