Star Trek: The Next Generation - 5x02 - Darmok

    The Enterprise goes to work on establishing relations with another alien species.  All prior attempts have been friendly, but they can't communicate.  Things seem to be heading the same way.  Then the aliens transport their captain and Picard to the surface of the planet nearby, where the pair of them wander around, and are eventually attacked by some weird invisible creature.  Picard eventually figures out how the other captain communicates.  They talk by using metaphors from their cultural history.
    This is a fun episode, and it's memorable.  But it is honestly one of the least believable premises they've used.  Most of the outlandish Trek plots can be excused, since they use science as a story device.  In this case, the aliens using metaphors to communicate is just completely absurd.  Some ideas can be communicated this way.  But the system is absurdly inefficient for explaining complex ideas.  How did these aliens ever build a spaceship?  I'd expect a language like this for Jar Jar.  Not for a Trek universe species.