All the kids grow 10 feet tall... and TAKE OVER!
"Genius" accidentally invents "goo" which causes living things to rapidly grow to an enormous size. Seeing an opportunity to get rich, some delinquent teenagers steal the "goo" and, as a result of a sophomoric dare, consume it themselves and become thirty feet tall. They then take over control of the town by kidnapping the sheriff's daughter and dancing suggestively.
