Elvira is a wicked green witch who resides deep in a haunted swamp. BB and Lukey's curiosity draws them to the edge of her homestead. As they approach the swamp, they encounter the evil Cajun fairies know as feux follets. A beautiful feu follet lures Lukey into the swamp, and Pop-Pop and BB attempt to rescue him. The feu follet succeeds, and BB, Lukey, and Pop-Pop are lost in the haunted swamp. During their quest to find their way out, elements within the swamp engage their presence.

BB and the Feu Follet is the sixth book of the BB series. The story takes place in my hometown of Opelousas, Louisiana, located in the heart of Louisiana's Cajun bayou country.