A Hollyrock film company goes on location in Bedrock to film its new feature "The Monster from the Tar Pits," and gullible Fred is enlisted as stand-in for star Gary Granite. However, Fred's real problems begin when Wilma and Betty audition for roles in the film and end up going crazy upon meeting movie stars Rock Pile and Wednesday Tuesday.

To finance their dream of opening a pool hall, Fred and Barney visit the dinosaur racetrack where Fred bets his entire paycheck on a long shot. To cover for gambling, Fred pretends to have been beaten by a robber and tells Wilma that he has lost his check. When the longshot pays off, Fred and Barney are initially elated but quickly realize their problems are only beginning.