It could be Mork's last night on Earth when an ancient Orkan elder who looks like a ten-year-old boy arrives with the news that Mork must return to Ork for “forecycling" because he has picked up too many Earthly ways.
Mork, lonely in Mindy's absence, sets the stage for amazing comical confusion when he gets the visiting Orkan Elder to clone multiple Mindys which he continues to do until he gets it right.