For the World Is Hollow and I Have Touched the Sky

This was an episode of the original Star Trek series that I really liked. Several millenniums ago a civilized race built a giant spaceship and camouflaged it with material to make it look like a moon that was detached from planetary orbit. The reason was to make sure no one looked at it with any suspicions and that the chosen survivors would arrive at a new world and just take up the civilization again.

It's gone horribly wrong and the ship never really arrived and now the humanoids living there don't even realize they're living inside a giant ship. The artificial sun and stars are their world. And they've got a giant computer which has taken control and everyone on the ship has a control device implanted in their heads so they never question the will of the 'oracle' or their origins.

More than that has gone wrong, the ship is on a collision course with an inhabited Federation planet which brings the Enterprise on a mission to save their associated planet. They discover it is indeed not a floating asteroid or moon, but has signs of life.

Deforest Kelley gets a little romance here. He's got a disease that no doubt he diagnosed himself and has months to live. He and high priestess of the oracle Kate Woodville fall for each other and that doesn't stop her from defending her way of life as she sees it.

An interesting concept that Star Trek deals with is the notion that a place they come to thinks they are the center of a universe. That is something we earth folks had to learn and some of us still haven't.

The Prime Directive about non-interference is something that William Shatner concludes doesn't apply when we're saving two planets from total annihilation. How Shatner and Leonard Nimoy do it you have to see this episode for.