Billy, a portly, pug-nosed kid who likes to take risks, agrees to a bet with his friend Alan: If he eats 15 worms in 15 days, Alan will pay him $50. To do this, Billy must face his many fears and bad habits, including his disgust for worms, his fondness for junk food, and his fears about being poisoned.

He’s ably assisted by Tom, except during several days after Tom refuses Billy’s challenge to eat a worm himself and instead runs away. During those alone times, Billy discovers he can manage the preparation and eating of worms without Tom’s help. The reader witnesses the development of Billy’s independence and self-confidence. These traits come to replace the others, like fear or dependence, that formerly defined him.

Billy overcomes his opponents’s every attempt to scare, fool, or trick him; he also finds his way toward remaining friends with them after the bet is over. While Billy’s victory is sweet, Rockwell’s greatest lesson is the value of friendship.

As the primary protagonist, Billy’s adventure serves to deliver a host of moral lessons. As a realistic character with human flaws and foibles, many young readers relate to Billy. By inhabiting his story and his evolution, the readers experience its aphorisms: It’s ok to be afraid, but you shouldn’t let it stop you; sometimes you’ll be alone and have to depend on yourself to navigate challenging circumstances; at other times, it’s teamwork that breeds success; and finally, friendship is the sweetest reward of all.