In the conclusion of the four-part story "The War Machines," the robot army created by power-hungry computer WOTAN (Will Operating Thought Analogue) continues its devastating attack on London. The only hope for mankind's survival rests with the Doctor (William Hartnell), who reasons that the only way to stop a supercomputer is by deploying another supercomputer. With this episode, Anneke Wells and Michael Craze become series regulars in the roles of Polly and Ben. Scripted by Ian Stuart Black from a story idea by Kit Pedler, "The War Machines, Episode Four" first aired on July 2, 1966, as the final episode of Doctor Who's third season. ~ Hal Erickson, Rovi