Bickley is doing what Bickley does best: throwing cold water on parties. About a dozen of Mindy's friends were in her apartment playing Tangle. As they all fall over, Bickley knocks on the door complaining that it sounds like R2D2 doing a tap shoe. He also complains about the noise that ice cubes make when they rattle in glasses. And he complains about bodily sounds, presumably flatulence, which Julius apologizes for. When he threatens to stage a sit in until the guests leave, they walk out together at 8:30.
The next day, Mindy cannot locate her "Mindy" necklace, and Fred jokingly suggests that she poll everyone at the party and ask if they're a thief. Mork not only takes Fred's advice seriously, but he mistakes photos in Mindy's high school yearbook for mug shots, and calls her entire graduating class to accuse them of stealing.
As Mork completes his round of phone calls, Mindy comes home from the grocery store with tonight's dinner: pork ribs and a melon for dessert. Mork mistakes the melon for a basketball, and smashes the melon onto the floor, which provokes more complaints from Bickley.
When Bickley leaves, Mindy discovers that the pork ribs are gone, and Mork discovers that his Orkan Age Machine (see the A Mommy for Morky episode) is missing too. As all this took place within just moments, it is obvious that Bickley is the thief.
That the age machine is in someone else's hands soon becomes obvious as well. Bickley thinks it to be a pocket calculator, and randomly presses buttons. Mork alternates between toddler, middle age, adolescent, and infant in rapid transit time. When Bickley starts doing square roots, Mork is sent back to his descendent species, the chicken. Mork, playing a chicken, falls out the second story window.
A police officer brings Mork home, and Mindy admits to his living there. Mork is back to his normal age, but dressed/covered in a large plastic garbage bag, for he has molted. The officer considers arresting him for "pecking an officer," but reconsiders. Evidently Mork was trying to evolve a joke – by crossing the road.
Mork and Mindy decide it is time to confront Bickley. When Bickley is found not home, and the door is unlocked, they decide to go in and search around. They find the stolen articles, but Bickley comes home before they can leave. Bickley comes in doting on Bickey, the now-grown puppy that Mork gave him in the episode Mork the Tolerant. As Mork and Mindy hide, Bickley among other things praises Bickey for not excluding him from his activities. It becomes clear that what Bickley really objected to was not being invited to her party.
Mork exposes his hiding place, and Mork and Mindy are caught. As they accuse each other of being thieves, Bickley admits to have stolen a lot more than what Mork and Mindy had come down for. They do reach common ground when Mindy agrees to include Bickley in her parties. As they leave with their new understanding, Mork stuffs Bickley's radio down his shirt. And Bickley warns Mork not to play his stolen radio too loud.
Mork reports to Orson about loneliness. He reports bourbon as medicine to take while suffering from loneliness, and he reports the curiosity that loneliness is self-inflicted. When Orson suggests that earthlings get together to find a cure for loneliness, Mork spots a paradox: If they did that, the assembly itself would override the need to find a cure.