Frazer Hines

Investigating the disappearance of an eminent scientist, the Doctor and his companions follow his trail to the London headquarters of International Electromatics, a global supplier of electronic equipment run by the formidable Tobias Vaughn. Teaming up with the newly formed United Nations Intelligence Taskforce (UNIT) under the command of Brigadier Lethbridge-Stewart, the Doctor soon suspects that Vaughn is working to his own sinister agenda. As Cybermen...

The Tardis arrives on a extinct volcanic island. Before long, the travelers are captured and taken into the depths of the Earth, where they find a hidden civilization, the lost city of Atlantis. The Atlanteans worship a goddess named Amdo and use Fish People, men and women operated upon so that they can breathe under the sea, to farm the plankton-based food on which they survive.