'Miri' by Adrian Spies

Answering an ancient distress signal, the crew of the Enterprise are amazed to discover an unnamed planet that appears to be an exact duplicate of Earth. Captain Kirk takes a landing party and beams down to the planet surface; here they find a dead and decaying world resembling that of the 1960s. After encountering a young girl named Miri, they learn that there are no adults left alive on the planet; three-hundred years ago, scientists attempted to prolong the lifespans of the inhabitants, but instead their experiments created a deadly virus which killed all the grown ups through rapid aging and madness. However, the virus greatly slowed the natural aging process of the children, giving them centuries of prepubescent existence. Every member of the landing party contracts the virus, except for Lieutenant Commander Spock, who becomes a carrier; until Doctor McCoy can find a cure for the disease, they must be confined to the planet surface. Kirk and the others attempt to befriend a rag-tag band of children, but their leader, an angry boy named Jahn, refuses to have anything to do with them. Miri falls in love with Kirk, and happily assists him and the others while they search for a cure. But when Miri then sees Yeoman Rand as a rival for the captain's affections, she runs away in anger - and decides to help Jahn in inciting the children in a campaign to kill Kirk and the others…

William Shatner (Captain James Tiberius Kirk), Leonard Nimoy (First Officer Lieutenant Commander Spock), DeForest Kelley (Doctor Leonard H. ‘Bones’ McCoy), Kim Darby (Miri), Michael J. Pollard (Jahn), Grace Lee Whitney (Yeoman Janice Rand), Jim Goodwin (Lieutenant John Farrell), David L. Ross (Lieutenant Galloway)

Directed by Vincent McEveety

TX:
27th October, 1966

Notes:
*Featuring Captain James Tiberius Kirk, First Officer Lieutenant Commander Spock, Doctor Leonard H. ‘Bones’ McCoy, and Yeoman Janice Rand