When Sir Reginald Styles claims to have seen a ghost, UNIT is called in. The Doctor and Jo spend the night at Styles' house and become the target of an assassin.
A captive of the guerrillas, the Doctor discovers they intend to change history. Jo is transported to the 22nd Century where she unwittingly gives vital information to the Daleks.
The Doctor arrives in a bleak future where Earth is ruled by the Daleks and mankind is enslaved. Rescuing Jo, the two escape but the brutish Ogrons are in pursuit.
The Controller betrays the Daleks and is exterminated. The Daleks travel back in time to the 20th Century to ensure that the peace conference fails.
