When 11-year-old Steven Sweeney is tricked into drinking a strange mixture of chemicals by his classmates, things begin to get strange. Either his toothbrush is growing, or he is shrinking! Steven has to navigate his way through gigantic dust bunnies, enormous birds, and other once seemingly harmless, everyday items to get to his best friend's house for help. Will he be able to make it through the day and return to his original size?