Inept handyman Ernest (Jim Varney) is a fixture at Chippewa Falls High School. Setting out to repair a leaky faucet, Ernest turns a men's room into a flood disaster area. Enter bureaucrat Mr. Axwell (Kevin McNulty), who proclaims that all school employees must have a high school diploma. After predictably disastrous encounters with classroom learning, Ernest is saved from a pink slip by two excitable German scientists on the faculty, Gerta (Linda Kash) and Bobby (Bill Byrge). Ernest is to be the guinea pig in their sub-atomic brain stimulation experiment and must regularly receive an infusion of the smarts.