Simon Bar Sinister and his henchman Cad are fast at work on a new chemical: shrinking water that will shrink the people of the city to the size of Simon's thumb. To prevent Underdog from foiling him again, Simon corners Polly and shrinks her with the shrinking water hidden inside his squirting flower. Simon puts the TV reporter inside a birdcage at his lab. Polly calls for Underdog, who also falls prey to Simon's new evil invention.