With the merciless Melkur in control of The Source, the Doctor and his allies have only a slim chance of deposing him, which also puts the peace of the Traken Union in severe jeopardy.

Starring:

Elisabeth Sladen, Frazer Hines, Jacqueline Hill, John Levene, John Scott Martin, Jon Pertwee, Katy Manning, Nicholas Courtney, Pat Gorman, Patrick Troughton, Peter Davison, Tom Baker, William Hartnell, William Russell

Genre:

Adventure, Drama, Sci-Fi