Sherman Klump is working on a new miracle formula– this time, the fountain of youth. He is also preparing to marry a fellow scientist and girlfriend, Denise Gaines (Janet Jackson). Unfortunately, he has started suffering from personality lapses that are threatening to alienate his bride-to-be: against his will, he acts like the obnoxious Buddy Love of the first film. After a particularly unpleasant incident, Sherman goes to his lab to analyze his DNA and locates Buddy Love's DNA in an abnormal gene. He decides to use Denise's genetic research methods to isolate the gene and permanently extract Buddy Love's DNA from his own. His assistant, Jason, tries to stop him, warning him that he might damage his health or even lose his intelligence. Sherman disregards the warning and, alone in his lab