The Doctor and companions land on an island with a pyramid shaped tower. I saw that tower and thought Atlantis but the story had nothing to do with Atlantis, so much for that. In any case they immediately fall into intrigue and a planet full of mysterious peoples. The tower contained a remnant of the technological development of the people of that planet, it contained a machine that broadcast a signal which made everybody agreeable and peaceful. But some were not affected by the machine and there had been a war etc. The machine was operated by five keys, and the keys had been scattered for safekeeping. The Doctor and Companions then are sent on a quest to travel across the planet and recover all the keys.
As I said they come across many strange peoples. It is a very misleading story full of twists and turns.
The first place they visit is the City of Morphoton seemingly inhabited by a race of gentle people who have everything they need and willingly give all that's desired by the Doctor and Companions. However it's all a hypnotic illusion and they barely escape without being enslaved.
The story goes on like this -- there is an outpost in a jungle where a mad scientist has somehow unlocked the secret of amazingly fast plant growth, creating the jungle. Another place is in snowy mountains with a rogue who attempts to trick the Companions and kill them by stranding them in the blizzard. The final place is a city in which one of the Companions is accidentally implicated in murder.
About the Author(s)
David Herron is a writer and software engineer focusing on the wise use of technology. He is especially interested in clean energy technologies like solar power, wind power, and electric cars. David worked for nearly 30 years in Silicon Valley on software ranging from electronic mail systems, to video streaming, to the Java programming language, and has published several books on Node.js programming and electric vehicles.