The Westley kids stumble upon Sunny's old school yearbook and mistake his years in a funk band for a tour of duty as a pirate. They find a treasure map that leads to a cave where they awaken and unleash a toxic Sloppy Joe blob. Sunny himself has a connection to the blob and he and the kids must work together to save the day.

Sunny encounters a mad scientist named Dr. Nefario who tries to destroy him, while he also sets up a concert dedicated to his old mentor, who he believes has no faith in him, after their original Student-Teacher relation.