Mitch Forrester and his wife Helen have packed their boys into the family station wagon and are heading to a new town with a new job for Mitch and a new elementary school for their son Billy. It seems to Billy that everybody else, including his little brother Woody, easily adapts to the new surroundings. Billy's fears are realized in his first moments at the new school when the old adage 'everybody picks on the new kid' appears to be true. Everybody except the tall, lanky girl named Erika Tanzy whose kindness simultaneously inspires gratefulness and humiliation in Billy. When the school bully Joe and his band of 5th grade followers put worms in Billy's lunch, Billy surprises them all when he stands up to and embarrasses Joe. This leads the two to make a bet: on Saturday Billy must eat 10 worms by 7PM. When his parents leave Woody in his care, Billy presses Erika into service to help keep an eye on Woody and to lend him some moral support in his gastronomic challenge. Joe's gang makes each worm more delightfully revolting than the last, beginning with La Big Porker, which is fried in pig fat. This odyssey through worm cuisine takes the boys all over town as they try to force Billy to throw up by dubbing each specimen increasingly disgusting names like The Burning Fireball, The Greasy Brown Toad Bloater Special, and The Barfmallow. When the adventure finally ends up down by the river for worms such as The Green Slusher and Radioactive Slime Delight, all of the kids learn the true meaning of friendship and bravery, as well as the difficulties and importance of doing the right thing.