In the fifth episode of the seven-part story arc "The Daleks," the Doctor (William Hartnell) and his companions are still faced with the twin dilemmas of escaping back to the 20th century and preventing the mutant Daleks from detonating a neutron bomb that will destroy the planet Skaro. With all but Susan (Carole Ann Ford) having fallen ill from radiation poisoning, it is left to Susan to return to the time-jumping TARDIS. Her journey is fraught with peril, but she receives unexpected assistance from a band of humanoids called the Thals. Written by Terry Nation, "The Expedition" first aired on January 18, 1964.
by Hal Erickson synopsis