‘Mork & Mindy’
Mork & Mindy “ended” in perhaps the most confusing way possible. By Season 4, the show had run its course with the fans, so ABC canceled it. Unfortunately, that season was set to end on an epic cliffhanger, where Mork and Mindy escape a renegade alien, Mork’s alien identity becomes public, Mindy’s apartment gets destroyed, and the two find themselves traveling through time to escape their enemy. They wind up in the prehistoric era, with seemingly no hope of returning. Since we never got a Season 5, they never did.
According to writer Brian Levant, in an interview with io9, Season 5 apparently had Mork and Mindy traveling through various points in time, meeting historical figures and presumably doing wacky things with them. Levant mentions photoshoots of Mork, Mindy, Benjamin Franklin, and Abraham Lincoln, so clearly they were serious about this, until the big cancel anyway. Adding to the confusion, the show decided not to technically end the series on the cliffhanger, instead running a random “on Earth” episode last, one where Mork tries to earn a promotion from his Supreme Leader. The audience is left to assume they made it back to modern times, solved the villain problem, and fixed Mindy’s apartment lickety-split, without telling anyone.