When Mrs. Barnes declares that "It's Apple Day," Dumpy wants to help and finally gets his chance once all of the apples are picked and made into pies, apple butter, and candy apples.

Can Dumpy the Dump Truck feed the farm animals and move the pigs to their new pen in time to take Charlie to the school bus?

With help from an eccentric professor who gives their imaginations special intensive training, three children succeed in locating the last of the great Whangdoodles and granting his heart's desire.