Star Trek The Original Series Rewatch: "And the Children Shall Lead"
Stardate: 5029.5 Captain’s log. Kirk, Spock, and McCoy beam down to Triacus, a scientific outpost, responding to a distress call. They materialize to find a whole lot of dead bodies. There’s only one survivor: Professor Starnes, but he dies after a minute, and he doesn’t recognize Kirk before he croaks. One of the corpses has a bottle of poison in her mouth, and Starnes’s last log entry on his tricorder indicates that they have to all kill themselves because of the enemy within. (Gee, that would make a great title…) A bunch of kids run out and start playing, completely oblivious to ...
Source: tor.com