Doctor Who: Meglos

On the lush planet Tigella, two opposing factions are divided over the usage of the Dodecahedron, an ancient and powerful artefact which provides the entire planet's energy. The Doctor is summoned to arbitrate the conflict, but the power-crazed Meglos intercepts the call and impersonates him in order to steal the Dodecahedron.

Cast: Tom Baker, Lalla Ward, John Leeson, Bill Fraser, Frederick Treves, Edward Underdown