Last updated 24 March 2024


Episode 1

Series Episode Number: 198

World Premiere: Sat 16 Mar 1968 - 5:14pm BST [BBC One] (United Kingdom)
First Broadcast: Sun 21 Mar 2021 - 6:00pm EDT [BBC America]
Running Time: 24 minutes 54 seconds

8.20 Million (UK)

Appreciation Index: 55 (UK)

Chart Position: 46 () (UK)

Recorded on Sat 24 Feb 1968 in Lime Grove D
Archive State: Missing



The Doctor, Jamie and Victoria find themselves on the east coast of England where a gas refinery is experiencing problems and a sinister heartbeat is throbbing through the pipes.