1 September 1979
Tim Barlow (Tyssan), Peter Straker (Commander Sharrel), Suzanne Danielle (Agella), Tony Osoba (Lan), Mike Mungarvan, Cy Town (Dalek Operators), Roy Skelton (Dalek Voices), David Gooderson (Davros) [2-4], Penny Casdagli (Jall) [2, 4], David Yip (Veldan) [2, 4], Cassandra (Movellan Guard) 
|Written by||Terry Nation|
|Directed by||Ken Grieve|
|Produced by||Graham Williams|
|1||“Part One”||24:03||1 September 1979||13m|
|2||“Part Two”||25:14||8 September 1979||12.7m|
|3||“Part Three”||24:32||15 September 1979||13.8m|
|4||“Part Four”||26:05||22 September 1979||14.4m|
Accompanied by the newly regenerated Romana, The Doctor lands on a mystery planet intrigued by the evidence of drilling taking place there, deep underground. The discoveries he makes are chilling. For the planet is Skaro and the Daleks are in charge of the operation. But just what are his old enemies searching for? And why?
Perhaps the answers lie with the Movellans, a beautiful humanoid race led by Commander Sharrel. They are waging a war of their own with the Daleks and the situation is now stalemate. Should The Doctor tip the balance of power to aid the Daleks’ ultimate destruction? Or are their intentions no less sinister than the Daleks’ themselves? Suddenly The Doctor finds himself enmeshed in a deadly battle which could result in the destruction of the universe itself as, once more, he summons the strength to face an all too familiar, timelessly evil adversary.