Afraid that his family will embarrass him at the school's upcoming Parent-Teacher Night, Spencer comes up with an idea: a snail can shrink the school - no school means no Parent-Teacher Night! But he decides to sleep on it, needing to think about the details. Unfortunately, Sunny draws the snail who goes on to shrink the school. Things are all right, at first, but soon, Spencer finds that he can't play with his classmates and friends, Angus and Eggman. Why? No school means no class and no class means no classmates! So, Spencer must figure out a way to bring back the school, which still has the principal and the teacher, Miss Spell, inside!