Some ten thousand years before the 23rd century, the Fabrini sun went nova. Towards the end, the Fabrini were living underground. Some of them, who later became known as the Creators, built the asteroid spaceship Yonada, crewed the ship with the choicest candidates, and sent the ship into space. For the people who stayed behind on the planet, they were destroyed by the sun's nova.
By the 23rd century, the fate of the Fabrini, as well as their system of writing, were familiar to the Federation, although their medical knowledge was not.
In 2268, the USS Enterprise intercepted the worldship Yonada which was on a collision course with the populated planet Daran V. Inside this fabricated asteroid, they discovered a population of Fabrini survivors on a predetermined course for a colony planet. The ship was controlled by a powerful computer, but over the years this computer came to be perceived by the Fabrini as a god, referred to as the Oracle of the People, as they lost all of their old knowledge of their origins.
The crew of the Enterprise was able to correct the navigational error and get the worldship back on its original course, simultaneously deactivating the Oracle and allowing the Fabrini to make their own way.
The Fabrini had sophisticated medical knowledge; they possessed the cure for xenopolycythemia, a disease for which, in the mid-23rd century, the Federation had no cure. (TOS: "For the World is Hollow and I Have Touched the Sky")