"And the Children Shall Lead" is a third season episode of the original science fiction television series, Star Trek, and was broadcast October 11, 1968. It is episode #59, production #60, written by Edward J. Lakso and directed by Marvin Chomsky.

In this episode, on a distant planet, Kirk, Spock and McCoy find a scientific team dead, and their children who, unknown to the crew, have great powers at their disposal.

Intercepting a distress call, the USS Enterprise arrives at the planet Triacus. Captain Kirk, Dr. McCoy, and First Officer Spock beam down to investigate just in time to witness the death of Professor Starnes, the leader of a scientific expedition. The other members of the expedition, apart from their five seemingly unconcerned children, seem to have died at their own hands.

The crew bring the children back to the Enterprise, where McCoy evaluates them and determines that they are suffering lacunar amnesia, unaware of what happened to their parents and unable to grieve. However, when left unattended in one of the ship's rooms, the children chant an invocation and summon a glowing humanoid apparition named Gorgan, who advises them to take control of the crew and spurs them on by saying, "As you believe, so shall you do, so shall you do." At Gorgan's direction, the eldest child, Tommy, uses mental powers to trick the crew into steering the ship towards Marcus XII while presenting illusions that make them think they are still in orbit above Triacus.

Upon reviewing troublesome expedition film recorded by Starnes, Spock, McCoy, and Kirk return to the bridge to find the children and Gorgan fully in control of the crew. Unable to break their hold on the crew, Spock observes that the children are merely possessed by Gorgan, who must be the evil embodiment of an ancient group of space-warring marauders released by Starnes's archaeological survey.

Believing they can break the hold Gorgan has on the children, Spock plays back footage showing the children happy with their parents, who are then shown to be dead. As the children realize what has happened, they break down emotionally and Gorgan's appearance begins to deteriorate. With the children's powers gone, the crew regains control and Kirk orders a course for Starbase 4 while they take care to comfort the children.

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