After witnessing the accidental death of a friend who was attempting to rescue him from bullies, an African-American boy blames himself and, stricken with guilt, hides out among underground street people in New York.

When his mother sends Jack off with money to buy groceries, he comes home with a magic supercharged dirt bike instead. His mother is furious, but when Jack uses the magic bike to save the local hot dog stand from the clutches of corrupt big business, he becomes the town hero.