It's Halloween, and Pine Hollow Stables is getting some special visitors—a group of city kids. The Saddle Club girls are planning a treasure hunt and trick-or-treating for the children. Best of all, Stevie Lake's old school chum, Dinah, has come to help. Stevie can't wait to pull some pranks on her friend!

Things go awry when it becomes clear that Dinah and Saddle Club member Lisa Atwood don't like each other. Lisa suspects Dinah of flirting with Stevie's boyfriend. Even worse, Stevie's beginning to think the stable is haunted. Who's playing tricks at Pine Hollow?