Doctor Who Terminus: Part Four (1963–1989) watch online HD

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.

Peter Davison was against Sarah Sutton leaving, as he felt that Nyssa was the most appropriate companion for his Doctor. John Nathan-Turner felt that the character had run her course.

The Doctor kissing Nyssa on the cheek as she departs was devised by Peter Davison and Sarah Sutton. Originally, they were just going to shake hands.

This episode was watched by 7.4 million viewers on its original transmission.