The six-part Dr. Who adventure "Dalek Invasion of Earth" gets under way when the TARDIS materializes in 22nd century England. Trapped outside of their time-traveling vessel, the Doctor (William Hartnell) and his companions quickly learn that the Earth has been taken over by the mutant Daleks from the planet Skaro. Before the Doctor can do anything with this knowledge, his granddaughter Susan (Carole Ann Ford) vanishes, and Barbara (Jacqueline Hill) is seriously injured. Written by Terry Nation, "World's End" first aired on November 21, 1964. ~ Hal Erickson, Rovi