In Green Town, Illinois, the twelve year-old boys Will Halloway and Jim Nightshade are neighbors and best friends. Will's father Charles Halloway is an old man and the local librarian while Jim and his mother wait for the return of the return of their father and husband that will never occur. The boys know everyone in town, including their school teacher Miss Foley that misses her beauty and youth; the lonely barber Mr. Crosetti that has no girlfriend or wife; the greedy owner of a cigar store Mr.
Tetley that is obsessed with money; and the bartender Ed that has severed arm and leg and dreams on being a football hero. One day, Jim buys a lightning rod from the salesman Tom Fury that tells that a storm is coming. During the night, the boys overhear a mysterious train and they run through the woods to see the arrival but they do not see a living soul. However, they find the Mr. Dark's Pandemonium Carnival ready to be enjoyed and they snoop around. Soon they realize that frustrated and greedy people are vanishing in town and the evil Mr. Dark and the Dust Witch make their dreams come true. In return, Mr.
Dark seizes their souls. Now Mr. Dark is seeking them out but Charles Halloway has a journal from his father about the autumn carnival that might be their last chance to defeat the evil..