Parts: 4
Writer: David Agnew (Douglas Adams and Graham Williams; story by David Fisher)
Airdates: 29 September 1979 - 20 October 1979
Production Code: 5H

Doctor: fourth
Companions: the second Romana, K-9 mark two

Megalomaniac of the Week: Scaroth

Story: In a Parisian château, wealthy Count Scarlioni is employing the talented Professor Kerensky to conduct experiments involving time. Kerensky has been able to accelerate the growth of chickens, which he believes will solve the problem of world hunger. The Count has other ideas.

The fourth Doctor and Romana are in Paris, too, enjoying a well-deserved holiday. As they pause to rest in a café, they detect a slip in time - all of a sudden, the events of the past few seconds replay themselves. Romana is concerned, but the Doctor shrugs it off. They are on holiday, and nothing is going to spoil it.

Unfortunately, something does - Scarlioni, otherwise known as Scaroth, last of the Jagaroth. His spacecraft exploded above Earth in 400 million BC, causing him to splinter into twelve versions of himself scattered along the timeline, and incidentally providing the spark that created life on Earth. Now Scaroth wants to go back in time and stop himself from making the fatal mistake - but if he succeeds, he will cause everything on Earth to have never existed at all.