Episode Behind the Scenes

TREKCORE > TAS > EPISODES > THE PRACTICAL JOKER > Behind the Scenes
 
Although it is called the "Rec Room", this episode essentially is the first appearance of the holodeck, and summarily, the holodeck malfunction.
   
In a forgivable continuity error, when Kirk and Mr. Spock investigate the fog, the "KIRK IS A JERK" on Kirk's back disappears.
   
In a rare occurrence, Lieutenant Arex is seen in command of the Enterprise.
   
The idea of picking up an alien stowaway from an energy cloud was later seen again, to a much less comical degree in the "Star Trek: The Next Generation" episode "Lonely Among Us" as well as the "Star Trek: Voyager" episode "Alter Ego."