Grandpa invents a potion to turn a frog into a prince for Marilyn, but as usual it didn't work. While alone one night, Marilyn discovers that she has been locked in her room. Shouting for help, a passerby climbs the trellis to lend her a hand. While describing the family and her situation to the rescuer, he gets the impression she is being held prisoner by monsters. Grandpa of course believes his potion has worked after meeting Marilyn's rescuer.