Junior is a preteen worm who struggles to be accepted by his peers, only to get bullied for being spoiled by his overprotective mother. One day, while in an attempt to impress his friends, he is accidentally brought up to the surface by a shovel, thus starting a journey with great adventures and very high stakes - not only for the little hero, but also to the entire worms society. To get back home and save his own kind, Junior must first learn the powers of self-respect, trust and true friendship.