In the sixth episode of the 12-part story "The Dalek Masterplan," the Doctor (William Hartnell) has aligned himself with the valiant Sara Kingdom (Jean Marsh) in his efforts to foil the mass-destruction plans of the dreaded Daleks. Things come to a head when the crew of the TARDIS is forced into a showdown with a full complement of Dalek warriors. In a disturbing turn of events, the Doctor and Sara are compelled to leave Steven (Peter Purves) to face the Daleks all alone. Written by Dennis Spooner, "Coronas of the Sun" originally aired on December 18, 1965; this episode apparently no longer exists. ~ Hal Erickson, Rovi