There is a Star Trek Voyager episode where three humanoids on a planet survived a natural disaster that destroyed their planet by going into stasis and having t

There is a Star Trek Voyager episode where three humanoids on a planet survived a natural disaster that destroyed their planet by going into stasis and having their brains stimulated by a computer simulation for over 19 years. In that time, the adaptive computer responded to their worst fears by turning the "fun" model world full of clowns and dancers into a circus nightmare. The virtual characters created to entertain the survivors turned into sinister clowns. The head clown, and the manifestation of fear itself, has full access to their brains and would adapt to circumvent any attempts by them to leave his world or terminate the stasis.