TOS:Dagger of the Mind

The Enterprise gets an unexpected delivery when they exchange supplies for reports at the Tantalus penal colony. When they return to the Tantalus colony with their highly agitated visitor, Kirk beams down with a psychologist he has "met before" (Spock's expression at this is priceless; so subtle, yet makes clear that he knows what it means when a woman has "met" Kirk). The patients become the counselors, and the doctors become the treated. Like many Star Trek episodes,this has an underlying moral thems; in this case, at what price does a cure come?