1/4 The Doctor and Jo land on planet Peladon which is hoping to join the Galactic...
4/4 The Daleks travel back in time to ensure that the peace conference fails.
3/4 The Doctor arrives in a future where Earth is ruled by the Daleks.
2/4 The Doctor learns of a plot to change history and Jo is transported to the 22nd Century.
1/4 When Sir Reginald Styles claims to have seen a ghost, UNIT is called in.