 The Flintstones and the Rubbles take a vacation to Rockapulco leaving the kids to Mrs.Slaghoople. However, Fred takes Mexico so exotically that he grows a mustache and passes himself as El Terrifico, a secret agent who can do a lot of stuff, including bull fighting. As the rest are a bit annoyed of this arrogance, a couple of jewel smugglers, Rocco and Stella, want to take advantage of Fred s naive attitude, despite the fact that Wilma does not like the sexy looks of Stella.