A strange affliction that removes all of a person's inhibitions infects the crew of the Enterprise, allowing all the actors to ham it up. Nurse Chapel hits on Spock, Spock weeps about his mother, Kirk expresses romantic love for his ship, an Irish crewman hews to stereotype, and, best of all, Sulu takes off his shirt, brandishes a foil, and begins challenging people to duels.
As for Scotty, he gets to say, "I can't change the laws of physics," shortly before the crew resolves the situation by traveling back in time.
George Takei, who portrayed Sulu, has said that this is his favorite episode.
