The Doctor and Jo visit the Master in his high-security prison on an island off the south coast of England. The governor, Colonel Trenchard, says ships have been disappearing mysteriously at sea. The Doctor discovers that Trenchard and the Master are in league to contact the Sea Devils, a race of reptiles in hibernation in a base beneath the sea, who have been awoken by recent work on a nearby sea fort. The Master intends to use his new allies to help him conquer the world!

Genres

Cast

Jon Pertwee

The Doctor

Roger Delgado

The Master

Katy Manning

Jo Grant

Edwin Richfield

Captain Hart

Clive Morton

Trenchard

Donald Sumpter

Commander Ridgeway

David Griffin

Lt. Commander Mitchell

Royston Tickner

Robbins

Pat Gorman

Sea Devil

Peter Forbes-Robertson

Chief Sea Devil

Terry Walsh

Castle Guard Barclay

Martin Boddey

Walker