8 March 1975
Michael Wisher (Davros), Peter Miles (Nyder), Dennis Chinnery (Gharman) [1-2, 4-6], Guy Siner (Ravon) [1, 3], John Franklin-Robbins (Time Lord) , Richard Reeves (Kaled Leader) [1-3], John Scott Martin, Cy Town [3-6], Keith Ashley [3-6] (Dalek Operators), Stephen Yardley (Sevrin) [2-6], James Garbutt (Ronson) [2-4], Drew Wood (Tane) , Jeremy Chandler (Gerrill) , Pat Gorman , Hilary Minster  (Thal Soldiers), Tom Georgeson (Kavell) [3-5], Ivor Roberts (Mogran) , Michael Lynch (Thal Politician) [3-4], Max Faulkner (Thal Guard) , Roy Skelton (Dalek Voice) [3-6], Harriet Philpin (Bettan) [4-6], Peter Mantle (Kaled Guard) , Andrew Johns (Kravos) , John Gleeson (Thal Soldier) .
|Written by||Terry Nation|
|Directed by||David Maloney|
|Produced by||Philip Hinchcliffe|
The Time Lords intercept The Doctor, Sarah and Harry as they transmat back to Nerva, and send them to Skaro in the distant past in order to prevent the creation of the Daleks. There they discover the planet’s two native races, the Kaleds and the Thals, are nearing the climax of the Thousand Year War. As the conflict reaches its terrible conclusion, Sarah discovers that a disfigured Kaled scientist named Davros has already accomplished what the time travellers were sent to stop: the genesis of the Daleks.