Fifth grader Marcus "Mucus" McBain and his best friends, Walter, Sam, and Tex, always find a way to have fun. Whether searching for a misplaced, expensive baseball card, being forced to attend manners class, or playing for one of the worst baseball teams in Little League history, it is no secret that the fabulous foursome relies on orneriness, imagination, and a whole lot of determination to seek out adventure in their California town.

As the boys progress through fifth grade, they share many laughter-filled moments, usually at the expense of their nemesis, high school football player...