Holl, Keith Doyle's best friend, has finally tied the knot with his beloved, Maura in the Little Folks' new home, Hollow Tree Farm. Keith has good news of his own: he has started on an internship as a copywriter with a Chicago advertising agency, coming up with slogans and designs for new products, but the project he is really enthusiastic over is chasing air sprites in a hot air balloon. Unfortunately, one of the agency's client businesses is using the Little Folks' land as a dump for toxic waste. Holl's young cousin Dola sees them do it, but they see her, too. To prevent anyone else from finding out, then men kidnap her and Holl and Maura's new baby, Asrai. All of the Little Folk are called in to hunt for them. Keith reaches out to the new and wonderful air creatures he's found in hopes of bringing the baby and her brave guardian back to the farm.