The Enterprise crew encounter a ship disguised as an asteroid on a collision course with the planet Daran V. Its inhabitants are the descendants of an alien race called the Fabrini, whose planet was destroyed long ago. Aboard their multi-generational ship, they have forgotten their original purpose over time (or they weren’t allowed to know … More Hitting a Wall, TOS: S3E8 “For the World is Hollow and I have Touched the Sky”