Apartment manager Mr. Tyler (Alan DeWitt) has had enough of the "barbarian" antics of the cave family. He threatens to evict them on grounds that Breer (Pat Cardi) is truant, having never been enrolled in school. His parents Gronk (Joe E. Ross) and Shad (Imogene Coca) realize he must go to school, even though they don't know what it is. Astronauts Mac (Frank Aletter) and Hector (Jack Mullaney) struggle to answer entrance questions at the school and give Breer's last name as Sonagronk. The kids instantly laugh at his primitive attire upon walking into class (defying logic that the astronauts would have bought him appropriate clothes). Nonetheless, his fur loincloth eventually starts a fashion trend among the other boys. Breer learns some basic math and geography but explains it in a way that makes the Gronk family turn against the school. They go to Miss Fenway (Jackie Russell) and ridicule her in front of the students, sending her in tears to Principal Pettijohn (Alan Oppenheimer). Back in the apartment, Gronk explains that the world was created by a giant turtle meeting a magic egg. Mr. Pettijohn shows up to protest their actions at school, but is satisfied by the suggestion that Gronk and Shad go to night school for an education. They walk into the class of Mr. Babcock (Herb Vigran) as he is giving a history lecture of prehistoric man who thinks it is a prank. He somehow is an expert on the behaviors and thoughts of prehistoric people from 100 million B.C., but is shown more by Gronk and Shad. One act threatens the entire class, sending them scurrying for safety.
Looking through the plot holes, there's some funny lines, mostly by Joe E. Ross. By this point in the series it is very clear that the stars of the show are now Joe E. Ross and Imogene Coca, and rightfully so. After the format change to the present-day, it seems as if the writers don't really know what to do with the astronauts, except to re-use the plot of trying to get the general to believe they brought back a prehistoric family.
