Mork was a misfit on his own planet because of his sense of humor. So the humorless Orkans sent him off to study Earthlings, whose "crazy" customs they had never been able to understand. Mork landed, in a giant eggshell, near Boulder, Colorado. There he was befriended by pretty Mindy McConnell, a clerk at a music store run by her father, Frederick. Mork looked human, but his strange mixture of Orkan and Earthling customs such as wearing a suit, but putting it on backwards, or sitting in a chair, but upside down, led most people to think of him as just some kind of a nut. Mindy knew where he came from, and helped him adjust to Earth's strange ways. She also let him stay in the attic of her apartment house, which scandalized her conservative father, but not her swinging grandmother, Cora.

After a season of simple slapstick and big ratings, both the producers and the network violated one of television's cardinal rules: "Don't tamper with a hit." In the process of doing so, they almost destroyed the program. To start off the second season the producers decided to shift to more "meaningful" stories, the whole supporting cast was changed, and ABC moved the show from Thursday to Sunday nights. Confused viewers deserted the show in droves.

By December 1979 they scrambled to undo their mistakes. Mork went back to Thursday, stories got less complicated, and the dumped father and grandmother returned for the third season. Other changes included the addition of brother and sister Remo and Jean DaVinci who ran the New York Deli. Nelson was Mindy's uptight cousin with grandiose political ambitions; Mr. Bickley was the grouchy downstairs neighbor; Exidor was a crazed prophet and leader of an invisible cult. Mindy a journalism student, got a job at local TV station KTNS, where her boss was Mr. Sternhagen.