Third in the series. Holl returns from Ireland and finally marries his Maura, and they settle down to keep house in a tiny cottage on the grounds of Hollow Tree Farm. A year later, Keith Doyle has obtained a college internship at an advertising firm in Chicago, but he returns to his friends as often as he can. His new interest in ballooning is only a means of safely investigating the possibility of magical creatures living in the upper atmosphere.

The Little Folk are not aware they are being spied on until Dola and Holl's infant daughter are kidnapped. Keith, his balloonist friend Frank, and the frantic Holl set out in search, hoping to be successful before Keith has to go back to Chicago to present his advertising campaigns.