 A young kid named Genius accidentally invents a substance that causes all animal life to grow. Genius  sister Nancy and her boyfriend Mike see the money making potential in the substance dubbed goo and plan to sell it to help solve the world s food problem. Unfortunately, a greedy young opportunist named Fred and the group of delinquents he hangs around with decide to steal the goo and use it for their own purposes. They soon change their minds and decide to eat the goo themselves and grow to gigantic proportions and decide to take over the town. They then kidnap the sheriff s daughter and later Nancy as insurance to make sure that they get what they want. It is now up to Genius and Mike to either come up with more goo to enable Mike and his friends to grow and take on Fred and his gang or to find an antidote to shrink Fred and his gang back down to size.