The Doctor, played by William Hartnell, and a number of his companions take their T.A.R.D.I.S. time machine to the future only to discover that the Earth has been ravaged and taken over by a race of diabolical robots known as Daleks. Realizing that the Daleks are trying to mine the Earth's nuclear core, Dr. Who and company resolve to foil the Dalek's plan and save the future of the Earth.