The somewhat insane Doctor Proctor has accidentally invented the world's most powerful fart powder. When two kids from his neighborhood drop by for an unexpected visit, it becomes the beginning of an unusual friendship and a riotous business project. Well-behaved Lisa with her pigtails and tiny Nilly with his bright red hair decide to help introduce Doctor Proctor's fart powder to the world. But this turns out to be an adventure fraught with danger, as the wealthy and evil Mr. Thrane and his two creepy sons are willing to do anything to get their hands on the fart powder.