In the days leading up to Halloween in a Southern California suburb, 11-year-old Kenny and his best friend, Doug, play flag football, ride skateboards, get into mischief, and fend off the neighborhood bully, Johnny Hoffman. Ten-year-old Sherman, better known as "dumb ol' Sherman," lives across the street from Kenny and always tags along, making a nuisance of himself. Kenny falls in love with classmate Marcy, who spurns him, and he suffers the loss of Bob, his beloved but ailing dog. At school, Kenny interacts with his friendly teacher named Mr. Donovan, a foreign exchange student named Paco, and the class clown, Pudwell. As Halloween approaches, Kenny, Doug, and Sherman create their own crazy costumes, set off powerful firecrackers, go out unsupervised for trick-or-treating, and at the climax, pull a prank on a spooky old lady living in a haunted house.