Kurt Russell returns as Dexter Riley, the dedicated student of Medfield College who just can't stay out of trouble, in this follow-up to The Computer Wore Tennis Shoes and Now You See Him, Now You Don't. In this story, Dexter is trying to devise a formula for a chemistry project that will increase human strength . By accident, he discovers that, when he mixes his concoction with another student's recipe for vitamin-fortified cereal, it gives people super-human strength, but only for a few minutes. Ignoring these drawbacks, Dean Higgins (Joe Flynn) makes a deal to sell the miracle cereal to a leading breakfast-food concern, unaware that it's Dexter's secret ingredient that makes the cereal work. Meanwhile, when word gets out about the new strength-boosting cereal, several competing companies decide that they need to wipe the new product off the market. Cesar Romero returns from the first film as A.J. Arno, with Phil Silvers, Eve Arden, and Richard Bakalyan highlighting the supporting cast.
by Mark Deming synopsis