Can a spirit from the past come back to help us solve a problem in the present?

Twelve-year-old Marcie Horton is not looking forward to spending a lonely and boring summer at her grandparents' lake cottage. That is, until the woods near their home are threatened with development by the wealthy president of the university where her parents teach. Marcie is guided by the spirit of an Indian girl as she seeks to unlock the secrets of the past in her quest to save the centuries-old forest from development. Her effort is complicated by her growing friendship with the university president's popular daughter and the annual sailboat race, in which Marcie finds herself competing on the team of the wealthy summer house owners against the local residents. Marcie's success hinges on whether she can unravel the cryptic messages she receives in her dreams and visions from the mysterious spirit of the Indian girl, before the woods—and perhaps something much more important—are lost forever.